diff --git a/MODULE.bazel b/MODULE.bazel
index 015e4369a5..61ed91ca33 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -4,6 +4,7 @@ single_version_override(
     module_name = "toolchains_llvm_bootstrapped",
     patch_strip = 1,
     patches = [
+        "//patches:toolchains_llvm_bootstrapped_mingw_cfguard.patch",
         "//patches:toolchains_llvm_bootstrapped_resource_dir.patch",
     ],
 )
@@ -39,6 +40,10 @@ bazel_dep(name = "rules_rs", version = "0.0.23")
 archive_override(
     module_name = "rules_rs",
     integrity = "sha256-C5nTK7oyhrP+qWGx+AXHlWk4hz6PlC2F9sTvO/gM77g=",
+    patch_strip = 1,
+    patches = [
+        "//patches:rules_rs_windows_gnullvm_exec.patch",
+    ],
     strip_prefix = "rules_rs-7a47423f9f52de881b82beda8b1d8a76968775aa",
     url = "https://github.com/dzbarsky/rules_rs/archive/7a47423f9f52de881b82beda8b1d8a76968775aa.tar.gz",
 )
diff --git a/MODULE.bazel.lock b/MODULE.bazel.lock
index 07415816f9..ff6b423748 100644
--- a/MODULE.bazel.lock
+++ b/MODULE.bazel.lock
@@ -1503,16 +1503,18 @@
     },
     "@@rules_rs+//rs/experimental/toolchains:module_extension.bzl%toolchains": {
       "cargo-1.93.0-aarch64-apple-darwin.tar.xz": "6443909350322ad07f09bb5edfd9ff29268e6fe88c7d78bfba7a5e254248dc25",
-      "cargo-1.93.0-aarch64-pc-windows-gnullvm.tar.xz": "387832b989c8eb96c9ebd66402a87962167633bc6d91a49ffb8c7903c45f3476",
+      "cargo-1.93.0-aarch64-pc-windows-msvc.tar.xz": "155bff7a16aa7054e7ed7c3a82e362d4b302b3882d751b823e06ff63ae3f103d",
       "cargo-1.93.0-aarch64-unknown-linux-gnu.tar.xz": "5998940b8b97286bb67facb1a85535eeb3d4d7a61e36a85e386e5c0c5cfe5266",
       "cargo-1.93.0-x86_64-apple-darwin.tar.xz": "95a47c5ed797c35419908f04188d8b7de09946e71073c4b72632b16f5b10dfae",
       "cargo-1.93.0-x86_64-pc-windows-gnullvm.tar.xz": "f19766837559f90476508140cb95cc708220012ec00a854fa9f99187b1f246b6",
+      "cargo-1.93.0-x86_64-pc-windows-msvc.tar.xz": "e59c5e2baa9ec17261f2cda6676ebf7b68b21a860e3f7451c4d964728951da75",
       "cargo-1.93.0-x86_64-unknown-linux-gnu.tar.xz": "c23de3ae709ff33eed5e4ae59d1f9bcd75fa4dbaa9fb92f7b06bfb534b8db880",
       "clippy-1.93.0-aarch64-apple-darwin.tar.xz": "0b6e943a8d12be0e68575acf59c9ea102daf795055fcbbf862b0bfd35ec40039",
-      "clippy-1.93.0-aarch64-pc-windows-gnullvm.tar.xz": "296949f49be2de77ce9d1c5023a5f0a58e28e329eec03642a3da0e175a67beeb",
+      "clippy-1.93.0-aarch64-pc-windows-msvc.tar.xz": "07bcf2edb88cdf5ead2f02e4a8493e9b0ef935a31253fac6f9f3378d8023f113",
       "clippy-1.93.0-aarch64-unknown-linux-gnu.tar.xz": "872ae6d68d625946d281b91d928332e6b74f6ab269b6af842338df4338805a60",
       "clippy-1.93.0-x86_64-apple-darwin.tar.xz": "e6d0b1afb9607c14a1172d09ee194a032bbb3e48af913d55c5a473e0559eddde",
       "clippy-1.93.0-x86_64-pc-windows-gnullvm.tar.xz": "b6f1f7264ed6943c59dedfb9531fbadcc3c0fcf273c940a63d58898b14a1060f",
+      "clippy-1.93.0-x86_64-pc-windows-msvc.tar.xz": "25fb103390bf392980b4689ac09b2ec2ab4beefb7022a983215b613ad05eab57",
       "clippy-1.93.0-x86_64-unknown-linux-gnu.tar.xz": "793108977514b15c0f45ade28ae35c58b05370cb0f22e89bd98fdfa61eabf55d",
       "rust-std-1.93.0-aarch64-apple-darwin.tar.xz": "8603c63715349636ed85b4fe716c4e827a727918c840e54aff5b243cedadf19b",
       "rust-std-1.93.0-aarch64-apple-ios-macabi.tar.xz": "24d47e615ce101869ff452a572a6b77ed7cf70f2454d0b50892ac849e8c7ac4d",
@@ -1580,16 +1582,18 @@
       "rust-std-1.93.0-x86_64-unknown-none.tar.xz": "01dcca7ae4b7e82fbfa399adb5e160afaa13143e5a17e1e0737c38cf07365fb3",
       "rust-std-1.93.0-x86_64-unknown-uefi.tar.xz": "ec4e439d9485ce752b56999e8e41ed82373fc833a005cf2531c6f7ef7e785392",
       "rustc-1.93.0-aarch64-apple-darwin.tar.xz": "092be03c02b44c405dab1232541c84f32b2d9e8295747568c3d531dd137221dc",
-      "rustc-1.93.0-aarch64-pc-windows-gnullvm.tar.xz": "d3bc0cdaf157e20b1f23e510b5e3c4c6e9117d08f5284c04dee60aecff1bc851",
+      "rustc-1.93.0-aarch64-pc-windows-msvc.tar.xz": "a3ac1a8e411de8470f71b366f89d187718c431526912b181692ed0a18c56c7ad",
       "rustc-1.93.0-aarch64-unknown-linux-gnu.tar.xz": "1a9045695892ec08d8e9751bf7cf7db71fe27a6202dd12ce13aca48d0602dbde",
       "rustc-1.93.0-x86_64-apple-darwin.tar.xz": "594bb293f0a4f444656cf8dec2149fcb979c606260efee9e09bcf8c9c6ed6ae7",
       "rustc-1.93.0-x86_64-pc-windows-gnullvm.tar.xz": "0cdaa8de66f5ce21d1ea73917efc5c64f408bda49f678ddde19465ced9d5ec63",
+      "rustc-1.93.0-x86_64-pc-windows-msvc.tar.xz": "fa17677eee0d83eb055b309953184bf87ba634923d8897f860cda65d55c6e350",
       "rustc-1.93.0-x86_64-unknown-linux-gnu.tar.xz": "00c6e6740ea6a795e33568cd7514855d58408a1180cd820284a7bbf7c46af715",
       "rustfmt-1.93.0-aarch64-apple-darwin.tar.xz": "0dd1faedf0768ef362f4aae4424b34e8266f2b9cf5e76ea4fcaf780220b363a0",
-      "rustfmt-1.93.0-aarch64-pc-windows-gnullvm.tar.xz": "5888827e7fbd7d59930870b4856fce8d6d8fca5e02f6535f8ae3d7ad0ccf2d4a",
+      "rustfmt-1.93.0-aarch64-pc-windows-msvc.tar.xz": "24eed108489567133bbfe40c8eacda1567be55fae4c526911b39eb33eb27a6cb",
       "rustfmt-1.93.0-aarch64-unknown-linux-gnu.tar.xz": "92e1acb45ae642136258b4dabb39302af2d53c83e56ebd5858bc969f9e5c141a",
       "rustfmt-1.93.0-x86_64-apple-darwin.tar.xz": "c8453b4c5758eb39423042ffa9c23ed6128cbed2b15b581e5e1192c9cc0b1d4e",
       "rustfmt-1.93.0-x86_64-pc-windows-gnullvm.tar.xz": "47167e9e78db9be4503a060dee02f4df2cda252da32175dbf44331f965a747b9",
+      "rustfmt-1.93.0-x86_64-pc-windows-msvc.tar.xz": "5becc7c2dba4b9ab5199012cad30829235a7f7fb5d85a238697e8f0e44cbd9af",
       "rustfmt-1.93.0-x86_64-unknown-linux-gnu.tar.xz": "7f81f6c17d11a7fda5b4e1b111942fb3b23d30dcec767e13e340ebfb762a5e33"
     }
   }
diff --git a/patches/rules_rs_windows_gnullvm_exec.patch b/patches/rules_rs_windows_gnullvm_exec.patch
new file mode 100644
index 0000000000..a5c02a86db
--- /dev/null
+++ b/patches/rules_rs_windows_gnullvm_exec.patch
@@ -0,0 +1,115 @@
+diff --git a/rs/experimental/platforms/triples.bzl b/rs/experimental/platforms/triples.bzl
+index d4892e922..e4a3cd534 100644
+--- a/rs/experimental/platforms/triples.bzl
++++ b/rs/experimental/platforms/triples.bzl
+@@ -30,6 +30,7 @@ SUPPORTED_EXEC_TRIPLES = [
+     "x86_64-unknown-linux-gnu",
+     "aarch64-unknown-linux-gnu",
+     "x86_64-pc-windows-msvc",
++    "x86_64-pc-windows-gnullvm",
+     "aarch64-pc-windows-msvc",
+     "x86_64-apple-darwin",
+     "aarch64-apple-darwin",
+diff --git a/rs/experimental/toolchains/declare_toolchains.bzl b/rs/experimental/toolchains/declare_toolchains.bzl
+index 377e758eb..ab2908d14 100644
+--- a/rs/experimental/toolchains/declare_toolchains.bzl
++++ b/rs/experimental/toolchains/declare_toolchains.bzl
+@@ -12,6 +12,11 @@ def _channel(version):
+         return "beta"
+     return "stable"
+ 
++def _exec_triple_suffix(exec_triple):
++    if exec_triple.system == "windows":
++        return "{}_{}_{}".format(exec_triple.system, exec_triple.arch, exec_triple.abi)
++    return "{}_{}".format(exec_triple.system, exec_triple.arch)
++
+ def declare_toolchains(
+         *,
+         version,
+@@ -26,13 +31,12 @@ def declare_toolchains(
+     # Rustfmt
+     for triple in execs:
+         exec_triple = _parse_triple(triple)
+-        triple_suffix = exec_triple.system + "_" + exec_triple.arch
++        triple_suffix = _exec_triple_suffix(exec_triple)
+ 
+         repo_label = "@rust_toolchain_artifacts_{}_{}//:".format(triple_suffix, version_key)
+ 
+-        rustfmt_toolchain_name = "{}_{}_{}_rustfmt_toolchain".format(
+-            exec_triple.system,
+-            exec_triple.arch,
++        rustfmt_toolchain_name = "{}_{}_rustfmt_toolchain".format(
++            triple_suffix,
+             version_key,
+         )
+ 
+@@ -46,11 +50,8 @@ def declare_toolchains(
+         )
+ 
+         native.toolchain(
+-            name = "{}_{}_rustfmt_{}".format(exec_triple.system, exec_triple.arch, version_key),
+-            exec_compatible_with = [
+-                "@platforms//os:" + exec_triple.system,
+-                "@platforms//cpu:" + exec_triple.arch,
+-            ],
++            name = "{}_rustfmt_{}".format(triple_suffix, version_key),
++            exec_compatible_with = triple_to_constraint_set(triple),
+             target_compatible_with = [],
+             target_settings = [
+                 "@rules_rust//rust/toolchain/channel:" + channel,
+@@ -63,13 +64,12 @@ def declare_toolchains(
+     # Rustc
+     for triple in execs:
+         exec_triple = _parse_triple(triple)
+-        triple_suffix = exec_triple.system + "_" + exec_triple.arch
++        triple_suffix = _exec_triple_suffix(exec_triple)
+ 
+         repo_label = "@rust_toolchain_artifacts_{}_{}//:".format(triple_suffix, version_key)
+ 
+-        rust_toolchain_name = "{}_{}_{}_rust_toolchain".format(
+-            exec_triple.system,
+-            exec_triple.arch,
++        rust_toolchain_name = "{}_{}_rust_toolchain".format(
++            triple_suffix,
+             version_key,
+         )
+ 
+@@ -130,11 +130,8 @@ def declare_toolchains(
+             target_key = sanitize_triple(target_triple)
+ 
+             native.toolchain(
+-                name = "{}_{}_to_{}_{}".format(exec_triple.system, exec_triple.arch, target_key, version_key),
+-                exec_compatible_with = [
+-                    "@platforms//os:" + exec_triple.system,
+-                    "@platforms//cpu:" + exec_triple.arch,
+-                ],
++                name = "{}_to_{}_{}".format(triple_suffix, target_key, version_key),
++                exec_compatible_with = triple_to_constraint_set(triple),
+                 target_compatible_with = triple_to_constraint_set(target_triple),
+                 target_settings = [
+                     "@rules_rust//rust/toolchain/channel:" + channel,
+diff --git a/rs/experimental/toolchains/module_extension.bzl b/rs/experimental/toolchains/module_extension.bzl
+index 04477fefa..55fe0fce0 100644
+--- a/rs/experimental/toolchains/module_extension.bzl
++++ b/rs/experimental/toolchains/module_extension.bzl
+@@ -37,6 +37,11 @@ def _normalize_arch_name(arch):
+         return "aarch64"
+     return arch
+ 
++def _exec_triple_suffix(exec_triple):
++    if exec_triple.system == "windows":
++        return "{}_{}_{}".format(exec_triple.system, exec_triple.arch, exec_triple.abi)
++    return "{}_{}".format(exec_triple.system, exec_triple.arch)
++
+ def _sanitize_path_fragment(path):
+     return path.replace("/", "_").replace(":", "_")
+ 
+@@ -230,7 +235,7 @@ def _toolchains_impl(mctx):
+             if cargo_sha == None:
+                 fail("Could not determine cargo sha for {}".format(triple))
+ 
+-            triple_suffix = exec_triple.system + "_" + exec_triple.arch
++            triple_suffix = _exec_triple_suffix(exec_triple)
+ 
+             rust_toolchain_artifacts(
+                 name = "rust_toolchain_artifacts_{}_{}".format(triple_suffix, version_key),
diff --git a/patches/toolchains_llvm_bootstrapped_mingw_cfguard.patch b/patches/toolchains_llvm_bootstrapped_mingw_cfguard.patch
new file mode 100644
index 0000000000..67cabb0f71
--- /dev/null
+++ b/patches/toolchains_llvm_bootstrapped_mingw_cfguard.patch
@@ -0,0 +1,12 @@
+diff --git a/runtimes/mingw/crt_sources.bzl b/runtimes/mingw/crt_sources.bzl
+index 744f076..1a8a204 100644
+--- a/runtimes/mingw/crt_sources.bzl
++++ b/runtimes/mingw/crt_sources.bzl
+@@ -336,6 +336,7 @@ MINGWEX_TEXTUAL_SRCS = [
+ ]
+ 
+ MINGWEX_X86_SRCS = [
++    "cfguard/guard_dispatch.S",
+     "math/cbrtl.c",
+     "math/erfl.c",
+     "math/fdiml.c",