.EXE files are changed to .LNK files

hey, I'm having a big problem: last night I scanned my computer with ad-aware (a program against adware) and it found a ad program in my registry values and since I was very sleepy at that moment I just clicked fix, and this morning when i turned on my computer: explorer.exe wont launch, nearly all of my .exe files are now .LNK files, I've tried some forums and fixes on the net but still, nothing works!! please help me. sorry for my bad english