i just ran into this problem on a computer.
i started windows xp started up fine then try to start any program and it wont start. it thinks about starting an then stops i can run the windows games with np. but andy oter program like ms word or mozilla or even the restor program dosnt start. have to play with restarting and then sometimes it works. any idea what the problem is or what type of virus it might be? i also did windows repair thats when we where able to get programs to run until we restarted it.