Windows 11 home/ Win 10 Pro. How to prevent standard users from installing software? [closed]

Any user can run or install in its own user profile folder without admin privilege if the application don’t invoke admin right access or write file in restriction place.

You need AppLocker or such policy, which is available in Enterprise version, or use third part tool that can do that.

https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-application-control/applocker/applocker-overview