I have had this problem before actually.
I found that it was due to an update that had corrupted the OS.
Like people have already said, go into safe mode and do a System Restore.
If this doesnt work, then either it's a virus (which I doubt) or something deep seeded in the OS that cant be fixed through normal means, which means you will need to do a
complete format and reinstall of the OS.
Thanks for all the comments guys - i apprecite that you all trying to help - but here's the catch:
When i called Asus Support and did the Syster Restore/Recovery - the Computer cratches with a blue xcreen when loading the files. However, they told they have a solution for this, but I must first have a back up for the files i have in the HDD . Other than that - they are willin to guide me to recover my PC toll free.:)
Gurjiv, whats your Eve Call sign - PM it if you wish.