Something strange has happened. I can't run some command line executables in Windows anymore.

Steps:

• Open cmd
• Run an executable, such as ruby -v or git -h

When I do that, a new command prompt opens, running that command (I think, it's too fast to see), and instantly closes again.

I've managed to print screen the new command prompt, and it shows that it's running inside this path:
C:\Documents and Settings\Administrator\Local Settings\Temp\3582-490

Inside this folder, is the executable I'm tring to run.
If I run ruby, then ruby.exe is in there.
If I run git, then git.exe is in there. And it's always emptying the folder in between, so there is always just one .exe file