MSI installer uses 32-bit powershell for running the permission.ps1 script

[ikavalio]

Hi!

I've noticed that some of actions that CWA MSI installer runs on Windows are using 32-bit registry lookup and subsequently powershell to run permission.ps1 script. There is nothing wrong with that per se, it works on most setups, but in some rare cases, using 32-bit powershell is not desirable/possible in the 64-bit environment. Overriding POWERSHELLEXE parameters doesn't solve the issue completely as well, as 32-bit powershell is still being used under the hood:

Assuming everything about the CWA build and packaging is already 64-bit, is there any reason these operations remain 32-bit (at least from the consistency point of view)?

If I apply a few transformations to the default AWS MSI with just 2 changes equivalent to the following WSX operations, all subsequent operations are done by the 64-bit powershell:

• s/WixQuietExec/WixQuietExec64/ in

  amazon-cloudwatch-agent-test/msi/tools/amazon-cloudwatch-agent.wxs

  Lines 176 to 181 in df584e5

  	<CustomAction Id="QtExecUpdateConfigPermission"
  	BinaryKey="WixCA"
  	DllEntry="WixQuietExec"
  	Execute="deferred"
  	Return="check"
  	Impersonate="no" />

  . docs
• Add Win64='yes' to RegistrySearch in

  amazon-cloudwatch-agent-test/msi/tools/amazon-cloudwatch-agent.wxs

  Lines 28 to 32 in df584e5

  	<RegistrySearch Id="POWERSHELLEXE"
  	Type="raw"
  	Root="HKLM"
  	Key="SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell"
  	Name="Path" />

  docs

I'm happy to submit a patch if you think the changes above are a good idea, otherwise sorry for the noise!

Thanks in advance!

[subhobhai943]

Hi @ikavalio! 👋

I've implemented the exact solution you suggested and created PR #612 to fix this issue.

The changes include:

1. ✅ Added Win64='yes' to the RegistrySearch element for proper 64-bit registry lookup
2. ✅ Changed WixQuietExec to WixQuietExec64 in the CustomAction to use 64-bit PowerShell executor

This ensures all subsequent operations use 64-bit PowerShell consistently with the rest of the 64-bit CloudWatch Agent build.

Thanks for providing such a detailed issue description with the exact solution! 🚀