KB0001 - PSU Uninstall Error: "The setup must update files or services..."
When attempting to uninstall PowerShell Universal (MSI Install) from Control Panel -> Programs you receive the error:
"The setup must update files or services that cannot be updated while the system is running. If you choose to continue, a reboot will be required to complete the setup"
This is normal behavior because the PowerShell Universal service is still running. Your options here are to either:
1. Accept the prompt and reboot to continue the uninstallation
2. Cancel and then stop the PowerShell Universal service. You should then be able to try the uninstall again and it will complete without asking for reboot.