Ok, try next...
Even though exe file association is broken, you can actually run any exe, but you have to make sure you do this correctly.
Open taskmanager (since you know how to do this).
When your taskmanager is open... hold the control key and click on File > New Task (Run) in the menu.
It is important that you hold the control key when you select File > New Task (Run), otherwise it will open the "normal run" prompt. If you do this correctly, cmd.exe should open now.
IF it opens... It really should though,
then, in the cmdprompt, type next:
ftype exefile="%1" %*
Make sure you type it exactly as shown above.
Then Hit enter
It should look like this:
Then try if exe files work again, so doubleclick an exe file and see if it opens.
Edited by miekiemoes, 18 June 2008 - 03:23 PM.
edited to add extra instruction to restore the exefile association