diff --git a/Cargo.lock b/Cargo.lock
index 72ee70505c..996997dd95 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1260,6 +1260,7 @@ dependencies = [
 name = "net_util"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "base",
  "cfg-if",
  "cros_async",
@@ -1269,6 +1270,7 @@ dependencies = [
  "metrics",
  "net_sys",
  "pcap-file",
+ "prebuilts",
  "remain",
  "serde",
  "smallvec",
diff --git a/Cargo.toml b/Cargo.toml
index a7f590fd9f..13fdd76b47 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -130,7 +130,7 @@ all-linux = [
     "wl-dmabuf",
     "x",
     ]
-win64 = [ "balloon", "crash_report", "haxm", "stats" ]
+win64 = [ "balloon", "crash_report", "haxm", "slirp", "stats" ]
 arc_quota = ["devices/arc_quota"]
 audio = ["devices/audio"]
 audio_cras = ["devices/audio_cras"]
@@ -169,7 +169,7 @@ plugin = ["protos/plugin", "crosvm_plugin", "kvm", "kvm_sys", "protobuf"]
 plugin-render-server = []
 power-monitor-powerd = ["arch/power-monitor-powerd"]
 qcow = ["disk/qcow"]
-slirp = ["devices/slirp"]
+slirp = ["devices/slirp", "net_util/slirp"]
 stats = ["devices/stats"]
 tpm = ["devices/tpm"]
 usb = ["devices/usb"]
diff --git a/devices/src/virtio/mod.rs b/devices/src/virtio/mod.rs
index da9dd16f6b..f6c7ddcb19 100644
--- a/devices/src/virtio/mod.rs
+++ b/devices/src/virtio/mod.rs
@@ -15,7 +15,6 @@ mod interrupt;
 mod iommu;
 mod queue;
 mod rng;
-#[cfg(unix)]
 mod sys;
 #[cfg(any(feature = "tpm", feature = "vtpm"))]
 mod tpm;
@@ -80,6 +79,8 @@ cfg_if::cfg_if! {
 
         #[cfg(feature = "slirp")]
         pub use self::net::*;
+        #[cfg(feature = "slirp")]
+        pub use self::sys::windows::NetExt;
         pub use self::vsock::*;
     } else {
         compile_error!("Unsupported platform");
diff --git a/devices/src/virtio/vhost/user/device/net/sys/windows.rs b/devices/src/virtio/vhost/user/device/net/sys/windows.rs
index bc60143de1..628f9e9561 100644
--- a/devices/src/virtio/vhost/user/device/net/sys/windows.rs
+++ b/devices/src/virtio/vhost/user/device/net/sys/windows.rs
@@ -163,13 +163,11 @@ pub(in crate::virtio::vhost::user::device::net) fn start_queue<T: 'static + Into
                 let tap = ex
                     .async_from(tap)
                     .context("failed to create async tap device")?;
-                let read_notifier = base::Event(
-                    overlapped_wrapper
-                        .get_h_event_ref()
-                        .unwrap()
-                        .try_clone()
-                        .unwrap(),
-                );
+                let read_notifier = overlapped_wrapper
+                    .get_h_event_ref()
+                    .unwrap()
+                    .try_clone()
+                    .unwrap();
                 let read_notifier = EventAsync::new_without_reset(read_notifier, ex)
                     .context("failed to create async read notifier")?;
 
diff --git a/net_util/Cargo.toml b/net_util/Cargo.toml
index 0febfc7509..944faba5b4 100644
--- a/net_util/Cargo.toml
+++ b/net_util/Cargo.toml
@@ -17,7 +17,6 @@ cfg-if = "1.0.0"
 cros_async = { path = "../cros_async" }
 data_model = { path = "../common/data_model" }
 libc = "*"
-libslirp-sys = { version = "4.2.1", optional = true }
 
 net_sys = { path = "../net_sys" }
 pcap-file = { version = "1.1.0", optional = true }
@@ -30,3 +29,8 @@ virtio_sys = { path = "../virtio_sys" }
 [target.'cfg(windows)'.dependencies]
 metrics = { path = "../metrics" }
 winapi = { version = "*", features = ["everything", "std", "impl-default"] }
+libslirp-sys = { version = "4.2.1", optional = true }
+
+[build-dependencies]
+anyhow = "*"
+prebuilts = { path = "../prebuilts" }
diff --git a/net_util/build.rs b/net_util/build.rs
index 949bd71940..41684aa9b7 100644
--- a/net_util/build.rs
+++ b/net_util/build.rs
@@ -2,33 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#[cfg(all(feature = "slirp", windows))]
-mod win_slirp {
-    use std::env;
-
-    pub(super) fn main() {
-        // This must be an absolute path or linking issues will result when a consuming crate
-        // tries to link since $PWD will be different.
-        let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
-
-        #[cfg(debug_assertions)]
-        let build_type = "debug";
-
-        #[cfg(not(debug_assertions))]
-        let build_type = "release";
-
-        println!(
-            r#"cargo:rustc-link-search={}\..\..\..\third_party\libslirp\{}"#,
-            manifest_dir, build_type
-        );
-        println!(
-            r#"cargo:rustc-env=PATH={};{}\..\..\..\third_party\libslirp\{};"#,
-            env::var("PATH").unwrap(),
-            manifest_dir,
-            build_type,
-        );
-    }
-}
+static PREBUILTS_VERSION_FILENAME: &str = "prebuilts_version";
+static SLIRP_LIB: &str = "libslirp.lib";
+static SLIRP_DLL: &str = "libslirp-0.dll";
+#[cfg(unix)]
+static GLIB_FILENAME: &str = "libglib-2.0.dll.a";
 
 fn main() {
     // We (the Windows crosvm maintainers) submitted upstream patches to libslirp-sys so it doesn't
@@ -36,8 +14,27 @@ fn main() {
     // to the build system that invokes Cargo (e.g. the crosvm jCI scripts that also produce the
     // required libslirp DLL & lib). The integration here (win_slirp::main) is specific to crosvm's
     // build process.
-    #[cfg(all(feature = "slirp", windows))]
-    win_slirp::main();
+    if std::env::var("CARGO_CFG_WINDOWS").is_ok() {
+        let version = std::fs::read_to_string(PREBUILTS_VERSION_FILENAME)
+            .unwrap()
+            .trim()
+            .parse::<u32>()
+            .unwrap();
+        // TODO(b:242204245) build libslirp locally on windows from build.rs.
+        prebuilts::download_prebuilts(
+            "libslirp",
+            version,
+            &[
+                SLIRP_DLL,
+                SLIRP_LIB,
+                #[cfg(unix)]
+                // When compiling with mingw64 to run under wine64, we need glib as slirp links
+                // against it.
+                GLIB_FILENAME,
+            ],
+        )
+        .unwrap();
+    }
 
     // For unix, libslirp-sys's build script will make the appropriate linking calls to pkg_config.
 }
diff --git a/net_util/prebuilts_version b/net_util/prebuilts_version
new file mode 100644
index 0000000000..d00491fd7e
--- /dev/null
+++ b/net_util/prebuilts_version
@@ -0,0 +1 @@
+1
diff --git a/net_util/src/lib.rs b/net_util/src/lib.rs
index 737ca50be8..1cff1a35e4 100644
--- a/net_util/src/lib.rs
+++ b/net_util/src/lib.rs
@@ -33,6 +33,11 @@ use serde::Serialize;
 pub use sys::TapT;
 use thiserror::Error as ThisError;
 
+#[cfg(all(feature = "slirp"))]
+pub mod slirp;
+#[cfg(all(feature = "slirp", windows))]
+pub use slirp::Slirp;
+
 #[sorted]
 #[derive(ThisError, Debug)]
 pub enum Error {
@@ -51,18 +56,23 @@ pub enum Error {
     /// Couldn't open /dev/net/tun.
     #[error("failed to open /dev/net/tun: {0}")]
     OpenTun(SysError),
+    #[cfg(all(feature = "slirp", windows))]
+    #[error("slirp related error")]
+    Slirp(slirp::SlirpError),
 }
 
 pub type Result<T> = std::result::Result<T, Error>;
 
 impl Error {
     pub fn sys_error(&self) -> SysError {
-        match *self {
-            Error::CreateSocket(e) => e,
-            Error::OpenTun(e) => e,
-            Error::CreateTap(e) => e,
-            Error::CloneTap(e) => e,
-            Error::IoctlError(e) => e,
+        match &*self {
+            Error::CreateSocket(e) => *e,
+            Error::OpenTun(e) => *e,
+            Error::CreateTap(e) => *e,
+            Error::CloneTap(e) => *e,
+            Error::IoctlError(e) => *e,
+            #[cfg(all(feature = "slirp", windows))]
+            Error::Slirp(e) => e.sys_error(),
         }
     }
 }
diff --git a/net_util/src/slirp.rs b/net_util/src/slirp.rs
index fee082a519..da1fd25362 100644
--- a/net_util/src/slirp.rs
+++ b/net_util/src/slirp.rs
@@ -6,6 +6,8 @@
 //! level interfaces to libslirp that are used to implement that loop, and
 //! diagnostic tools.
 
+#![cfg(windows)]
+
 #[path = "../../third_party/libslirp-rs/src/context.rs"]
 pub mod context;
 
@@ -15,6 +17,44 @@ pub mod packet_ring_buffer;
 pub mod sys;
 pub use sys::Slirp;
 
+use base::Error as SysError;
+use remain::sorted;
+use thiserror::Error as ThisError;
+
 /// Length includes space for an ethernet frame & the vnet header. See the virtio spec for details:
 /// <http://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html#x1-2050006>
 pub const ETHERNET_FRAME_SIZE: usize = 1526;
+
+#[cfg(windows)]
+#[sorted]
+#[derive(ThisError, Debug)]
+pub enum SlirpError {
+    #[error("pipe was closed: {0}")]
+    BrokenPipe(std::io::Error),
+    #[error("failed to clone object: {0}")]
+    CloneFailed(std::io::Error),
+    #[error("overlapped operation failed: {0}")]
+    OverlappedError(std::io::Error),
+    /// Error encountered while in a Slirp related poll operation.
+    #[error("slirp poll failed: {0}")]
+    SlirpIOPollError(std::io::Error),
+    /// Error encountered while in a Slirp related poll operation.
+    #[error("slirp poll failed: {0}")]
+    SlirpPollError(SysError),
+    #[error("WSAStartup failed with code: {0}")]
+    WSAStartupError(SysError),
+}
+
+#[cfg(windows)]
+impl SlirpError {
+    pub fn sys_error(&self) -> SysError {
+        match &*self {
+            SlirpError::BrokenPipe(e) => SysError::new(e.raw_os_error().unwrap_or_default()),
+            SlirpError::CloneFailed(e) => SysError::new(e.raw_os_error().unwrap_or_default()),
+            SlirpError::OverlappedError(e) => SysError::new(e.raw_os_error().unwrap_or_default()),
+            SlirpError::SlirpIOPollError(e) => SysError::new(e.raw_os_error().unwrap_or_default()),
+            SlirpError::SlirpPollError(e) => *e,
+            SlirpError::WSAStartupError(e) => *e,
+        }
+    }
+}
diff --git a/net_util/src/slirp/sys/windows.rs b/net_util/src/slirp/sys/windows.rs
index 651df6d1a3..71001ea909 100644
--- a/net_util/src/slirp/sys/windows.rs
+++ b/net_util/src/slirp/sys/windows.rs
@@ -30,6 +30,7 @@ use cros_async::IntoAsync;
 use serde::Deserialize;
 use serde::Serialize;
 
+use crate::slirp::SlirpError;
 use crate::slirp::ETHERNET_FRAME_SIZE;
 use crate::Error;
 use crate::MacAddress;
@@ -69,7 +70,7 @@ impl Slirp {
             #[cfg(feature = "slirp-ring-capture")]
             let slirp_capture_file_clone = slirp_capture_file.clone();
             slirp_thread = thread::spawn(move || {
-                let disable_access_to_host = !cfg!("guest-to-host-net-loopback");
+                let disable_access_to_host = !cfg!(feature = "guest-to-host-net-loopback");
 
                 handler::start_slirp(
                     slirp_pipe,
@@ -100,7 +101,10 @@ impl Slirp {
 
     fn try_clone(&self) -> Result<Self> {
         Ok(Slirp {
-            guest_pipe: self.guest_pipe.try_clone().map_err(Error::CloneFailed)?,
+            guest_pipe: self
+                .guest_pipe
+                .try_clone()
+                .map_err(|e| Error::Slirp(SlirpError::CloneFailed(e)))?,
             overlapped_wrapper: OverlappedWrapper::new(true).unwrap(),
             slirp_thread: None,
         })
@@ -122,7 +126,7 @@ impl Slirp {
         // because libslirp logs *everything* as a debug entry.
         std::env::set_var("G_MESSAGES_DEBUG", "all");
 
-        let disable_access_to_host = !cfg!("guest-to-host-net-loopback");
+        let disable_access_to_host = !cfg!(feature = "guest-to-host-net-loopback");
 
         info!("starting slirp loop...");
         match handler::start_slirp(
@@ -132,7 +136,9 @@ impl Slirp {
             #[cfg(feature = "slirp-ring-capture")]
             slirp_capture_file.take(),
         ) {
-            Err(Error::BrokenPipe(e)) => warn!("exited slirp listening loop: {}", e),
+            Err(Error::Slirp(SlirpError::BrokenPipe(e))) => {
+                warn!("exited slirp listening loop: {}", e)
+            }
             Err(e) => panic!("error while running slirp listening loop: {}", e),
             _ => {}
         }
@@ -226,7 +232,7 @@ impl TapTCommon for Slirp {
         unimplemented!("not used by Slirp");
     }
 
-    fn if_flags(&self) -> i32 {
+    fn if_flags(&self) -> u32 {
         // This function is unused by the Slirp code paths.
         unimplemented!("not used by Slirp");
     }
diff --git a/net_util/src/slirp/sys/windows/handler.rs b/net_util/src/slirp/sys/windows/handler.rs
index 8cf8b543e8..d316a58865 100644
--- a/net_util/src/slirp/sys/windows/handler.rs
+++ b/net_util/src/slirp/sys/windows/handler.rs
@@ -21,20 +21,20 @@ use base::AsRawDescriptor;
 use base::Descriptor;
 use base::Error as SysError;
 use base::Event;
+use base::EventExt;
 use base::EventToken;
-use base::EventWindows;
 use base::RawDescriptor;
 use base::Timer;
 use base::WaitContext;
+use base::WaitContextExt;
 use data_model::DataInit;
-use data_model::Le16;
 use metrics::MetricEventType;
 use metrics::PeriodicLogger;
 #[cfg(any(feature = "slirp-ring-capture", feature = "slirp-debug"))]
 use pcap_file::pcap::PcapWriter;
 use smallvec::SmallVec;
-use virtio_sys::virtio_net_hdr;
-use virtio_sys::virtio_net_hdr_mrg_rxbuf;
+use virtio_sys::virtio_net::virtio_net_hdr;
+use virtio_sys::virtio_net::virtio_net_hdr_mrg_rxbuf;
 use winapi::shared::minwindef::MAKEWORD;
 use winapi::um::winnt::LONG;
 use winapi::um::winnt::SHORT;
@@ -61,6 +61,7 @@ use crate::slirp::context::Context;
 use crate::slirp::context::PollEvents;
 #[cfg(feature = "slirp-ring-capture")]
 use crate::slirp::packet_ring_buffer::PacketRingBuffer;
+use crate::slirp::SlirpError;
 use crate::slirp::ETHERNET_FRAME_SIZE;
 use crate::Error;
 use crate::Result;
@@ -113,7 +114,7 @@ impl CallbackHandler for Handler {
                 hdr_len: 0,
                 csum_start: 0,
                 csum_offset: 0,
-                gso_type: virtio_sys::VIRTIO_NET_HDR_GSO_NONE as u8,
+                gso_type: virtio_sys::virtio_net::VIRTIO_NET_HDR_GSO_NONE as u8,
             },
             num_buffers: 1,
         };
@@ -359,7 +360,7 @@ impl<'a> EventSelectedSocket<'a> {
             )
         };
         if res == SOCKET_ERROR {
-            return Err(Error::SlirpIOPollError(last_wsa_error()));
+            return Err(Error::Slirp(SlirpError::SlirpIOPollError(last_wsa_error())));
         }
         Ok(EventSelectedSocket { socket, event })
     }
@@ -402,28 +403,32 @@ fn poll<'a>(
         selected_sockets.push(EventSelectedSocket::new(*socket, socket_event_handle)?);
     }
 
-    wait_ctx.clear().map_err(Error::SlirpPollError)?;
+    wait_ctx
+        .clear()
+        .map_err(|e| Error::Slirp(SlirpError::SlirpPollError(e)))?;
     for (i, handle) in handles.iter().enumerate() {
         match wait_ctx.add(*handle, Token::EventHandleReady(i)) {
             Ok(v) => v,
             Err(e) => {
-                return Err(Error::SlirpPollError(e));
+                return Err(Error::Slirp(SlirpError::SlirpPollError(e)));
             }
         }
     }
     match wait_ctx.add(socket_event_handle, Token::SocketReady) {
         Ok(v) => v,
         Err(e) => {
-            return Err(Error::SlirpPollError(e));
+            return Err(Error::Slirp(SlirpError::SlirpPollError(e)));
         }
     }
 
     let events = if let Some(timeout) = timeout {
         wait_ctx
             .wait_timeout(timeout)
-            .map_err(Error::SlirpPollError)?
+            .map_err(|e| Error::Slirp(SlirpError::SlirpPollError(e)))?
     } else {
-        wait_ctx.wait().map_err(Error::SlirpPollError)?
+        wait_ctx
+            .wait()
+            .map_err(|e| Error::Slirp(SlirpError::SlirpPollError(e)))?
     };
 
     let tokens: Vec<Token> = events
@@ -446,7 +451,7 @@ fn poll<'a>(
     let socket_results = if sockets.is_empty() {
         Vec::new()
     } else {
-        poll_sockets(sockets).map_err(Error::SlirpIOPollError)?
+        poll_sockets(sockets).map_err(|e| Error::Slirp(SlirpError::SlirpIOPollError(e)))?
     };
 
     Ok((handle_results, socket_results))
@@ -466,7 +471,9 @@ impl WSAContext {
         // Safe because ctx.data is guaranteed to exist, and we check the return code.
         let err = unsafe { WSAStartup(MAKEWORD(2, 0), &mut ctx.data) };
         if err != 0 {
-            Err(Error::WSAStartupError(SysError::new(err)))
+            Err(Error::Slirp(SlirpError::WSAStartupError(SysError::new(
+                err,
+            ))))
         } else {
             Ok(ctx)
         }
@@ -506,8 +513,10 @@ pub fn start_slirp(
     let shutdown_event_handle = shutdown_event.as_raw_descriptor();
 
     // Stack data for the poll function.
-    let wait_ctx: WaitContext<Token> = WaitContext::new().map_err(Error::SlirpPollError)?;
-    let socket_event_handle = Event::new_auto_reset().map_err(Error::SlirpPollError)?;
+    let wait_ctx: WaitContext<Token> =
+        WaitContext::new().map_err(|e| Error::Slirp(SlirpError::SlirpPollError(e)))?;
+    let socket_event_handle =
+        Event::new_auto_reset().map_err(|e| Error::Slirp(SlirpError::SlirpPollError(e)))?;
 
     'slirp: loop {
         // Request the FDs that we should poll from Slirp. Slirp provides them to us by way of a
diff --git a/src/sys/windows/main.rs b/src/sys/windows/main.rs
index a9586454e9..0df0480eb6 100644
--- a/src/sys/windows/main.rs
+++ b/src/sys/windows/main.rs
@@ -74,6 +74,7 @@ pub(crate) fn run_slirp(args: RunSlirpCommand) -> Result<()> {
 
     let slirp_config = bootstrap_tube.recv::<SlirpStartupConfig>().unwrap();
 
+    #[cfg(feature = "sandbox")]
     if let Some(mut target) = sandbox::TargetServices::get()
         .exit_context(Exit::SandboxError, "sandbox operation failed")?
     {
diff --git a/third_party/libslirp-rs/src/context.rs b/third_party/libslirp-rs/src/context.rs
index 1908179657..d17dd2df8d 100644
--- a/third_party/libslirp-rs/src/context.rs
+++ b/third_party/libslirp-rs/src/context.rs
@@ -52,6 +52,7 @@ use base::error;
 use base::RawDescriptor;
 use libslirp_sys::*;
 
+use crate::slirp::SlirpError;
 use crate::Error;
 use crate::Result;
 
@@ -512,10 +513,10 @@ impl<H: CallbackHandler> Context<H> {
         assert!(!slirp.is_null());
         match ret.callback_handler.begin_read_from_guest() {
             Err(e) if e.kind() == std::io::ErrorKind::BrokenPipe => {
-                return Err(Error::BrokenPipe(e));
+                return Err(Error::Slirp(SlirpError::BrokenPipe(e)));
             }
             Err(e) => {
-                return Err(Error::OverlappedError(e));
+                return Err(Error::Slirp(SlirpError::OverlappedError(e)));
             }
             _ => {}
         }
@@ -545,15 +546,15 @@ impl<H: CallbackHandler> Context<H> {
                     break;
                 }
                 Err(e) if e.kind() == std::io::ErrorKind::BrokenPipe => {
-                    return Err(Error::BrokenPipe(e));
+                    return Err(Error::Slirp(SlirpError::BrokenPipe(e)));
                 }
                 Err(_) => {
                     match self.callback_handler.begin_read_from_guest() {
                         Err(e) if e.kind() == std::io::ErrorKind::BrokenPipe => {
-                            return Err(Error::BrokenPipe(e));
+                            return Err(Error::Slirp(SlirpError::BrokenPipe(e)));
                         }
                         Err(e) => {
-                            return Err(Error::OverlappedError(e));
+                            return Err(Error::Slirp(SlirpError::OverlappedError(e)));
                         }
                         _ => {}
                     }
@@ -562,10 +563,10 @@ impl<H: CallbackHandler> Context<H> {
             }
             match self.callback_handler.begin_read_from_guest() {
                 Err(e) if e.kind() == std::io::ErrorKind::BrokenPipe => {
-                    return Err(Error::BrokenPipe(e));
+                    return Err(Error::Slirp(SlirpError::BrokenPipe(e)));
                 }
                 Err(e) => {
-                    return Err(Error::OverlappedError(e));
+                    return Err(Error::Slirp(SlirpError::OverlappedError(e)));
                 }
                 _ => {}
             }
diff --git a/tools/install-deps b/tools/install-deps
index d79bac03f6..bf9371942b 100755
--- a/tools/install-deps
+++ b/tools/install-deps
@@ -22,7 +22,9 @@ sudo apt-get install --yes --no-install-recommends \
     libdbus-1-dev \
     libdrm-dev \
     libepoxy-dev \
+    libglib2.0-dev \
     libguestfs-tools \
+    libslirp-dev \
     libssl-dev \
     libswscale-dev \
     libudev-dev \