diff --git a/eng/pipelines/cdac/prepare-cdac-helix-steps.yml b/eng/pipelines/cdac/prepare-cdac-helix-steps.yml
index 1661d4eb2d1198..ce8e01605987ae 100644
--- a/eng/pipelines/cdac/prepare-cdac-helix-steps.yml
+++ b/eng/pipelines/cdac/prepare-cdac-helix-steps.yml
@@ -38,9 +38,11 @@ steps:
 
     $queue = switch ("$(osGroup)_$(archType)") {
         "windows_x64"  { "$(helix_windows_x64)" }
+        "windows_x86"  { "$(helix_windows_x64)" }
         "windows_arm64" { "$(helix_windows_arm64)" }
         "linux_x64"    { "$(helix_linux_x64_oldest)" }
         "linux_arm64"  { "$(helix_linux_arm64_oldest)" }
+        "linux_arm"    { "$(helix_linux_arm32_oldest)" }
         "osx_x64"     { "$(helix_macos_x64)" }
         "osx_arm64"   { "$(helix_macos_arm64)" }
         default        { Write-Error "Unsupported platform: $(osGroup)_$(archType)"; exit 1 }
diff --git a/eng/pipelines/helix-platforms.yml b/eng/pipelines/helix-platforms.yml
index e1ddcef6681bd8..3eacd890f6bc49 100644
--- a/eng/pipelines/helix-platforms.yml
+++ b/eng/pipelines/helix-platforms.yml
@@ -257,6 +257,10 @@ variables:
   - name: helix_windows_arm64_oldest_internal
     value: Windows.10.Arm64
 
+  # Windows x86 (runs on x64 machines via WoW64)
+  - name: helix_windows_x86
+    value: Windows.10.Amd64.Open
+
   # ===========================================
   # Browser/WASM Platforms
   # ===========================================
diff --git a/eng/pipelines/runtime-diagnostics.yml b/eng/pipelines/runtime-diagnostics.yml
index ceed70726cd270..87f93adfb62a85 100644
--- a/eng/pipelines/runtime-diagnostics.yml
+++ b/eng/pipelines/runtime-diagnostics.yml
@@ -10,9 +10,11 @@ parameters:
   type: object
   default:
     - windows_x64
+    - windows_x86
     - linux_x64
     - windows_arm64
     - linux_arm64
+    - linux_arm
     # TODO: Re-enable osx once disk space issue is resolved.
     # macOS full dumps are ~5.7GB each; with 8+ full-dump debuggees the Helix
     # machines run out of disk space (~45GB total). See PR #124782 for details.
@@ -216,11 +218,18 @@ extends:
               - template: /eng/pipelines/common/templates/runtimes/send-to-helix-inner-step.yml
                 parameters:
                   displayName: 'Send cDAC Dump Tests to Helix'
-                  sendParams: $(Build.SourcesDirectory)/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj /t:Test /p:TargetOS=$(osGroup) /p:TargetArchitecture=$(archType) /p:HelixTargetQueues=$(CdacHelixQueue) /p:TestHostPayload=$(TestHostPayloadDir) /p:DumpTestsPayload=$(Build.SourcesDirectory)/artifacts/helixPayload/cdac /bl:$(Build.SourcesDirectory)/artifacts/log/SendToHelix.binlog
+                  sendParams: $(Build.SourcesDirectory)/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj /t:Test /p:TargetOS=$(osGroup) /p:TargetArchitecture=$(archType) "/p:HelixTargetQueues=$(CdacHelixQueue)" /p:TestHostPayload=$(TestHostPayloadDir) /p:DumpTestsPayload=$(Build.SourcesDirectory)/artifacts/helixPayload/cdac /bl:$(Build.SourcesDirectory)/artifacts/log/SendToHelix.binlog
                   environment:
                     _Creator: dotnet-bot
                     SYSTEM_ACCESSTOKEN: $(System.AccessToken)
                     NUGET_PACKAGES: $(Build.SourcesDirectory)$(dir).packages
+              - task: PublishPipelineArtifact@1
+                inputs:
+                  targetPath: $(Build.SourcesDirectory)/artifacts/helixresults
+                  artifactName: CdacDumps_$(osGroup)_$(archType)
+                displayName: 'Publish Dump Artifacts'
+                condition: and(always(), ne(variables['Agent.JobStatus'], 'Succeeded'))
+                continueOnError: true
               - pwsh: |
                   if ("$(Agent.JobStatus)" -ne "Succeeded") {
                     Write-Error "One or more cDAC dump test failures were detected. Failing the job."
@@ -253,7 +262,7 @@ extends:
               - template: /eng/pipelines/common/templates/runtimes/send-to-helix-inner-step.yml
                 parameters:
                   displayName: 'Send cDAC Dump Gen to Helix'
-                  sendParams: $(Build.SourcesDirectory)/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj /t:Test /p:DumpOnly=true /p:TargetOS=$(osGroup) /p:TargetArchitecture=$(archType) /p:HelixTargetQueues=$(CdacHelixQueue) /p:TestHostPayload=$(TestHostPayloadDir) /p:DumpTestsPayload=$(Build.SourcesDirectory)/artifacts/helixPayload/cdac /bl:$(Build.SourcesDirectory)/artifacts/log/SendDumpGenToHelix.binlog
+                  sendParams: $(Build.SourcesDirectory)/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj /t:Test /p:DumpOnly=true /p:TargetOS=$(osGroup) /p:TargetArchitecture=$(archType) "/p:HelixTargetQueues=$(CdacHelixQueue)" /p:TestHostPayload=$(TestHostPayloadDir) /p:DumpTestsPayload=$(Build.SourcesDirectory)/artifacts/helixPayload/cdac /bl:$(Build.SourcesDirectory)/artifacts/log/SendDumpGenToHelix.binlog
                   environment:
                     _Creator: dotnet-bot
                     SYSTEM_ACCESSTOKEN: $(System.AccessToken)
@@ -329,7 +338,7 @@ extends:
               - template: /eng/pipelines/common/templates/runtimes/send-to-helix-inner-step.yml
                 parameters:
                   displayName: 'Send cDAC X-Plat Dump Tests to Helix'
-                  sendParams: $(Build.SourcesDirectory)/src/native/managed/cdac/tests/DumpTests/cdac-dump-xplat-test-helix.proj /t:Test /p:TargetOS=$(osGroup) /p:TargetArchitecture=$(archType) /p:HelixTargetQueues=$(CdacHelixQueue) /p:TestHostPayload=$(TestHostPayloadDir) /p:DumpTestsPayload=$(Build.SourcesDirectory)/artifacts/helixPayload/cdac /bl:$(Build.SourcesDirectory)/artifacts/log/SendXPlatTestToHelix.binlog
+                  sendParams: $(Build.SourcesDirectory)/src/native/managed/cdac/tests/DumpTests/cdac-dump-xplat-test-helix.proj /t:Test /p:TargetOS=$(osGroup) /p:TargetArchitecture=$(archType) "/p:HelixTargetQueues=$(CdacHelixQueue)" /p:TestHostPayload=$(TestHostPayloadDir) /p:DumpTestsPayload=$(Build.SourcesDirectory)/artifacts/helixPayload/cdac /bl:$(Build.SourcesDirectory)/artifacts/log/SendXPlatTestToHelix.binlog
                   environment:
                     _Creator: dotnet-bot
                     SYSTEM_ACCESSTOKEN: $(System.AccessToken)
diff --git a/src/native/managed/cdac/tests/DumpTests/DumpTests.targets b/src/native/managed/cdac/tests/DumpTests/DumpTests.targets
index 5ee2d6b3b0db04..3962b1f38d1f69 100644
--- a/src/native/managed/cdac/tests/DumpTests/DumpTests.targets
+++ b/src/native/managed/cdac/tests/DumpTests/DumpTests.targets
@@ -62,23 +62,8 @@
     <DumpRuntimeVersion Include="$(DumpVersions)" />
   </ItemGroup>
 
-  <!--
-    On Windows, heap dumps (type 2) require the DAC (mscordaccore.dll) which is unsigned
-    in local/CI builds. Set the DisableAuxProviderSignatureCheck registry value so that
-    MiniDumpWriteDump accepts the unsigned DAC. Windows 11+ / Server 2022+ only.
-
-    This is opt-in via /p:SetDisableAuxProviderSignatureCheck=true to avoid surprising
-    machine-wide registry changes during a normal build.
-  -->
-  <Target Name="_EnableUnsignedDacWindows"
-          BeforeTargets="GenerateAllDumps"
-          Condition="'$(HostOS)' == 'windows' AND '$(SetDisableAuxProviderSignatureCheck)' == 'true'">
-    <Exec Command="reg add &quot;HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\MiniDumpSettings&quot; /v DisableAuxProviderSignatureCheck /t REG_DWORD /d 1 /f"
-          IgnoreExitCode="true"
-          IgnoreStandardErrorWarningFormat="true" />
-    <Message Text="Note: If heap dump generation fails on Windows, ensure the DisableAuxProviderSignatureCheck registry key is set. Run as admin or set manually: reg add &quot;HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\MiniDumpSettings&quot; /v DisableAuxProviderSignatureCheck /t REG_DWORD /d 1 /f"
-             Importance="normal" />
-  </Target>
+  <!-- Unsigned DAC registry key for heap dumps (shared with cdac-dump-helix.proj) -->
+  <Import Project="EnableUnsignedDac.props" />
 
   <!-- Filter out Windows-only debuggees on non-Windows platforms. Debuggees opt in
        by setting <WindowsOnly>true</WindowsOnly> in their csproj. -->
diff --git a/src/native/managed/cdac/tests/DumpTests/EnableUnsignedDac.props b/src/native/managed/cdac/tests/DumpTests/EnableUnsignedDac.props
new file mode 100644
index 00000000000000..2ebdfd8a95da5c
--- /dev/null
+++ b/src/native/managed/cdac/tests/DumpTests/EnableUnsignedDac.props
@@ -0,0 +1,33 @@
+<Project>
+
+  <!--
+    On Windows, heap dumps (type 2) require the DAC (mscordaccore.dll) which is unsigned
+    in local/CI builds. Set the DisableAuxProviderSignatureCheck registry value so that
+    MiniDumpWriteDump accepts the unsigned DAC. Windows 11+ / Server 2022+ only.
+
+    The key must be set in both the native (64-bit) and WoW64 (32-bit) registry views.
+    Without /reg:32, x86 processes running under WoW64 read from
+    HKLM\SOFTWARE\WOW6432Node\... and miss the key, producing degraded dumps.
+  -->
+
+  <PropertyGroup>
+    <_DacRegKey>HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\MiniDumpSettings</_DacRegKey>
+    <_DacRegAdd>reg add &quot;$(_DacRegKey)&quot; /v DisableAuxProviderSignatureCheck /t REG_DWORD /d 1 /f</_DacRegAdd>
+    <_DacRegAdd32>$(_DacRegAdd) /reg:32</_DacRegAdd32>
+  </PropertyGroup>
+
+  <!--
+    MSBuild target for local/CI builds (opt-in via /p:SetDisableAuxProviderSignatureCheck=true).
+  -->
+  <Target Name="_EnableUnsignedDacWindows"
+          BeforeTargets="GenerateAllDumps"
+          Condition="'$(HostOS)' == 'windows' AND '$(SetDisableAuxProviderSignatureCheck)' == 'true'">
+    <Exec Command="$(_DacRegAdd)" IgnoreExitCode="true" IgnoreStandardErrorWarningFormat="true" />
+    <!-- WoW64 view only needed for x86 processes -->
+    <Exec Command="$(_DacRegAdd32)" IgnoreExitCode="true" IgnoreStandardErrorWarningFormat="true"
+          Condition="'$(TargetArchitecture)' == 'x86'" />
+    <Message Text="Note: If heap dump generation fails on Windows, ensure the DisableAuxProviderSignatureCheck registry key is set. Run as admin or set manually: $(_DacRegAdd)"
+             Importance="normal" />
+  </Target>
+
+</Project>
diff --git a/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj b/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj
index 9b89de9084d17e..8254b909449ae6 100644
--- a/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj
+++ b/src/native/managed/cdac/tests/DumpTests/cdac-dump-helix.proj
@@ -63,6 +63,7 @@
     derived from each debuggee's DumpTypes property (Heap->heap/2, Full->full/4).
   -->
   <Import Project="$(DumpTestsPayload)/debuggee-metadata.props" />
+  <Import Project="$(MSBuildThisFileDirectory)EnableUnsignedDac.props" />
 
   <!--
     Helix work item command: generate dumps then run tests (or tar + upload).
@@ -83,7 +84,8 @@
   <!-- Windows: test mode tail command -->
   <PropertyGroup Condition="'$(TargetOS)' == 'windows' AND '$(DumpOnly)' != 'true'">
     <_TestCommand>%HELIX_CORRELATION_PAYLOAD%\dotnet.exe exec --runtimeconfig %HELIX_WORKITEM_PAYLOAD%\tests\Microsoft.Diagnostics.DataContractReader.DumpTests.runtimeconfig.json --depsfile %HELIX_WORKITEM_PAYLOAD%\tests\Microsoft.Diagnostics.DataContractReader.DumpTests.deps.json %HELIX_WORKITEM_PAYLOAD%\tests\xunit.console.dll %HELIX_WORKITEM_PAYLOAD%\tests\Microsoft.Diagnostics.DataContractReader.DumpTests.dll -xml testResults.xml -nologo</_TestCommand>
-    <_FullCommand>$(_DumpGenCommands) &amp; $(_DumpInfoCommand) &amp; $(_TestCommand)</_FullCommand>
+    <_TarCommand>tar -czf %HELIX_WORKITEM_UPLOAD_ROOT%\dumps.tar.gz -C %HELIX_WORKITEM_PAYLOAD%\dumps .</_TarCommand>
+    <_FullCommand>$(_DumpGenCommands) &amp; $(_DumpInfoCommand) &amp; $(_TestCommand) &amp; $(_TarCommand)</_FullCommand>
   </PropertyGroup>
 
   <!-- Windows: DumpOnly mode tail command -->
@@ -101,7 +103,8 @@
   <!-- Unix: test mode tail command -->
   <PropertyGroup Condition="'$(TargetOS)' != 'windows' AND '$(DumpOnly)' != 'true'">
     <_TestCommand>$HELIX_CORRELATION_PAYLOAD/dotnet exec --runtimeconfig $HELIX_WORKITEM_PAYLOAD/tests/Microsoft.Diagnostics.DataContractReader.DumpTests.runtimeconfig.json --depsfile $HELIX_WORKITEM_PAYLOAD/tests/Microsoft.Diagnostics.DataContractReader.DumpTests.deps.json $HELIX_WORKITEM_PAYLOAD/tests/xunit.console.dll $HELIX_WORKITEM_PAYLOAD/tests/Microsoft.Diagnostics.DataContractReader.DumpTests.dll -xml testResults.xml -nologo</_TestCommand>
-    <_FullCommand>$(_DumpGenCommands) &amp;&amp; $(_DumpInfoCommand) &amp;&amp; $(_TestCommand)</_FullCommand>
+    <_TarCommand>tar -czf $HELIX_WORKITEM_UPLOAD_ROOT/dumps.tar.gz -C $HELIX_WORKITEM_PAYLOAD/dumps .</_TarCommand>
+    <_FullCommand>$(_DumpGenCommands) &amp;&amp; $(_DumpInfoCommand) &amp;&amp; $(_TestCommand) ; $(_TarCommand)</_FullCommand>
   </PropertyGroup>
 
   <!-- Unix: DumpOnly mode tail command -->
@@ -113,7 +116,9 @@
   <!-- Pre-commands: enable dump generation -->
   <ItemGroup Condition="'$(TargetOS)' == 'windows'">
     <!-- Allow heap dump generation with the unsigned locally-built DAC -->
-    <HelixPreCommand Include="reg add &quot;HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\MiniDumpSettings&quot; /v DisableAuxProviderSignatureCheck /t REG_DWORD /d 1 /f 2&gt;nul || (echo DisableAuxProviderSignatureCheck registry write skipped &amp; exit /b 0)" />
+    <HelixPreCommand Include="$(_DacRegAdd) 2&gt;nul || (echo DisableAuxProviderSignatureCheck registry write skipped &amp; exit /b 0)" />
+    <!-- WoW64 view only needed for x86 processes -->
+    <HelixPreCommand Condition="'$(TargetArchitecture)' == 'x86'" Include="$(_DacRegAdd32) 2&gt;nul || (echo DisableAuxProviderSignatureCheck /reg:32 registry write skipped &amp; exit /b 0)" />
     <HelixPreCommand Include="set DOTNET_DbgEnableMiniDump=1" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetOS)' != 'windows'">
@@ -133,12 +138,13 @@
     <HelixPreCommands>@(HelixPreCommand)</HelixPreCommands>
   </PropertyGroup>
 
-  <!-- Test mode: generate dumps then run tests -->
+  <!-- Test mode: generate dumps, run tests, then tar dumps for download on failure -->
   <ItemGroup Condition="'$(DumpOnly)' != 'true'">
     <HelixWorkItem Include="CdacDumpTests">
       <PayloadDirectory>$(DumpTestsPayload)</PayloadDirectory>
       <Command>$(_FullCommand)</Command>
       <Timeout>$(WorkItemTimeout)</Timeout>
+      <DownloadFilesFromResults>dumps.tar.gz</DownloadFilesFromResults>
     </HelixWorkItem>
   </ItemGroup>