I've downloaded the Quake 4 demo.exe from multiple locations and everytime I run the .exe I get the error "Quake4_demo.exe is not a valid win32 application".

Read: How to fix Not a valid Win32 application error? Does installing antivirus slow down a PC? Antivirus programs work in such a way as to know when you’re not gaming or using your computer and ...

I get "%1 is not a valid Win32 application" when trying to start the Microsoft MTA Stacks in COntrol Panel > Administrative Tools > ServicesI also get " is ...