Uhm, for uninstallers? How about Windows Installer?
If you mean in other contexts... I think the point is you're not intended to be able to do this? Outside of uninstallers, running code that only exists in RAM is... the type of thing malware typically wants to do more than anything else.
But in terms of what's physically possible, I suppose there's the command prompt, PowerShell, and scheduled tasks? I'm not sure if all of those can be disabled.