XP won't run .exe or .com files in safe mode

[holatronsys]

Hello,
How can I get Windows XP to run .exe and .com files again. It is not possible to run regedit or any downloaded programs, even in safe mode.

 

[me 1]

What is the actual message when you try to open an *.exe? (I need to know if it's a virus, a file association problem.......etc.)
Do U have a win xp cd?
Did it happened recent?
Do they have weird icons?