diff --git a/.github/actions/setup-msvc-dev-cmd/action.yml b/.github/actions/setup-msvc-dev-cmd/action.yml
new file mode 100644
index 0000000..87f0fc9
--- /dev/null
+++ b/.github/actions/setup-msvc-dev-cmd/action.yml
@@ -0,0 +1,85 @@
+name: Setup MSVC Developer Command Prompt
+description: Export MSVC developer environment variables for subsequent Windows build steps.
+inputs:
+  arch:
+    description: Target architecture passed to vcvarsall.bat, for example x64 or arm64.
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Export MSVC environment
+      shell: pwsh
+      run: |
+        $ErrorActionPreference = 'Stop'
+
+        $arch = '${{ inputs.arch }}'
+        $validArchitectures = @('x86', 'x64', 'arm', 'arm64')
+        if ($arch -notin $validArchitectures) {
+          throw "Unsupported MSVC architecture: $arch"
+        }
+
+        $vswhere = Join-Path ${env:ProgramFiles(x86)} 'Microsoft Visual Studio\Installer\vswhere.exe'
+        if (-not (Test-Path $vswhere)) {
+          throw "vswhere was not found: $vswhere"
+        }
+
+        $installationPath = & $vswhere -latest -products '*' -property installationPath
+        if (-not $installationPath) {
+          throw 'Visual Studio installation was not found'
+        }
+
+        $vcvarsall = Join-Path $installationPath 'VC\Auxiliary\Build\vcvarsall.bat'
+        if (-not (Test-Path $vcvarsall)) {
+          throw "vcvarsall.bat was not found: $vcvarsall"
+        }
+
+        $before = @{}
+        Get-ChildItem Env: | ForEach-Object {
+          $before[$_.Name] = $_.Value
+        }
+
+        $vcvarsCommand = "`"$vcvarsall`" $arch >nul && set"
+        $environment = & cmd.exe /s /c $vcvarsCommand
+        if ($LASTEXITCODE -ne 0) {
+          throw "vcvarsall.bat failed for architecture: $arch"
+        }
+
+        $preserveVariables = @(
+          'VCPKG_ROOT',
+          'VCPKG_INSTALLATION_ROOT',
+          'VCPKG_DEFAULT_BINARY_CACHE',
+          'VCPKG_DOWNLOADS'
+        )
+
+        foreach ($line in $environment) {
+          if ($line -notmatch '^([^=]+)=(.*)$') {
+            continue
+          }
+
+          $name = $Matches[1]
+          $value = $Matches[2]
+          if ($before.ContainsKey($name) -and $before[$name] -ceq $value) {
+            continue
+          }
+
+          if ($name -in $preserveVariables) {
+            continue
+          }
+
+          if ($name -ieq 'Path') {
+            # Preserve vcvarsall's PATH ordering. GITHUB_PATH prepends entries and
+            # can make Visual Studio's bundled vcpkg shadow the runner vcpkg.
+            $delimiter = "MSVC_ENV_$([guid]::NewGuid().ToString('N'))"
+            "$name<<$delimiter" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+            $value | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+            $delimiter | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+            continue
+          }
+
+          $delimiter = "MSVC_ENV_$([guid]::NewGuid().ToString('N'))"
+          "$name<<$delimiter" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+          $value | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+          $delimiter | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+        }
+
+        "MSVC developer environment initialized for $arch"
diff --git a/.github/actions/setup-native-prereqs/action.yml b/.github/actions/setup-native-prereqs/action.yml
index ed83ff3..e68d673 100644
--- a/.github/actions/setup-native-prereqs/action.yml
+++ b/.github/actions/setup-native-prereqs/action.yml
@@ -49,6 +49,8 @@ runs:
       if: endsWith(inputs.target, '-pc-windows-msvc')
       shell: pwsh
       run: |
+        $ErrorActionPreference = 'Stop'
+
         if ($env:VCPKG_DEFAULT_BINARY_CACHE) {
           New-Item -ItemType Directory -Force -Path $env:VCPKG_DEFAULT_BINARY_CACHE | Out-Null
         }
@@ -62,10 +64,27 @@ runs:
           default { throw "unsupported Windows target: ${{ inputs.target }}" }
         }
 
-        # vcpkg is pre-installed on GitHub-hosted Windows runners.
-        vcpkg install glib:$Triplet libusb:$Triplet fftw3:$Triplet pkgconf:$Triplet
+        $BundledVcpkg = 'C:\vcpkg\vcpkg.exe'
+        $ResolvedVcpkg = Get-Command vcpkg -CommandType Application -ErrorAction SilentlyContinue | Select-Object -First 1
+        $VcpkgExe = if (Test-Path $BundledVcpkg) {
+          $BundledVcpkg
+        } elseif ($ResolvedVcpkg) {
+          $ResolvedVcpkg.Source
+        } else {
+          throw 'vcpkg executable was not found'
+        }
+
+        $VcpkgRoot = Split-Path -Parent $VcpkgExe
+        $env:VCPKG_ROOT = $VcpkgRoot
+        $env:VCPKG_INSTALLATION_ROOT = $VcpkgRoot
+        Write-Host "Using vcpkg at $VcpkgExe"
+
+        $Packages = @("glib:$Triplet", "libusb:$Triplet", "fftw3:$Triplet", "pkgconf:$Triplet")
+        & $VcpkgExe install $Packages
+        if ($LASTEXITCODE -ne 0) {
+          throw "vcpkg install failed with exit code $LASTEXITCODE"
+        }
 
-        $VcpkgRoot = if ($env:VCPKG_INSTALLATION_ROOT) { $env:VCPKG_INSTALLATION_ROOT } elseif ($env:VCPKG_ROOT) { $env:VCPKG_ROOT } else { throw "vcpkg root environment variable is not set" }
         $PkgConfigExe = "$VcpkgRoot/installed/$Triplet/tools/pkgconf/pkgconf.exe"
         $PkgConfigPath = "$VcpkgRoot/installed/$Triplet/lib/pkgconfig;$VcpkgRoot/installed/$Triplet/share/pkgconfig"
         $PkgConfigBin = "$VcpkgRoot/installed/$Triplet/tools/pkgconf"
@@ -73,6 +92,7 @@ runs:
         $DebugRuntimeBin = "$VcpkgRoot/installed/$Triplet/debug/bin"
 
         "VCPKG_ROOT=$VcpkgRoot" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+        "VCPKG_INSTALLATION_ROOT=$VcpkgRoot" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
         "DSVIEW_VCPKG_ROOT=$VcpkgRoot" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
         "DSVIEW_VCPKG_TRIPLET=$Triplet" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
         "CMAKE_TOOLCHAIN_FILE=$VcpkgRoot/scripts/buildsystems/vcpkg.cmake" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f77775f..70f4ebb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -74,7 +74,7 @@ jobs:
 
       - name: Initialize MSVC developer command prompt
         if: contains(matrix.target, 'windows')
-        uses: ilammy/msvc-dev-cmd@v1
+        uses: ./.github/actions/setup-msvc-dev-cmd
         with:
           arch: ${{ matrix.msvc_arch }}
 
@@ -91,7 +91,7 @@ jobs:
 
       - name: Restore Windows vcpkg cache
         if: contains(matrix.target, 'windows')
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             .cache/vcpkg/binary
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 2d0ef14..c729f60 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -74,7 +74,7 @@ jobs:
 
       - name: Initialize MSVC developer command prompt
         if: contains(matrix.target, 'windows')
-        uses: ilammy/msvc-dev-cmd@v1
+        uses: ./.github/actions/setup-msvc-dev-cmd
         with:
           arch: ${{ matrix.msvc_arch }}
 
@@ -91,7 +91,7 @@ jobs:
 
       - name: Restore Windows vcpkg cache
         if: contains(matrix.target, 'windows')
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             .cache/vcpkg/binary