It just freezes for about 2 minutes and starts working again or it hangs on me and I have to reboot.When it freezes there is a 'tap' sound that the hard disk makes and its led light stops.Today it started to show that windows has performed an illegal operation.Any ideas the cause of this?

Anytime there is audible sound from a hard drive...I get rid of that hard drive. Noise is bad. I don't like bad things. Hence, getting rid of the bad thing makes me happy. I would say that this way of doing things is sound.

"Tapping" or "clicking" sounds from the drive, combined with abnormal behaviour such as the computer freezing up, could very well indicate that the drive is going bad. On the other hand, the symptoms could be caused by software corruption; either way though, the first thing I would suggest is to back up your data ASAP.

Can you give give us any more specific information on the "illegal operation" error?

Thats english for you " sound thinking, a sound solution to a sound problem" .Perhaps i should be quiet and go away.

The sound coming from the hard drive is prob. the read right heads o nthe disk it self..... touching the DISKS which isnt sopose to happen so what i would do and read careful... open the case and take the hdd out and take it apart and fix it and put it back togethor.. lol j/k throw it away and make us all happy.

Actually, that would be more of a grinding or whining/squealing noise.

A *tap* or *click* is usually more indicative of an engage/disengage problem with the head actuator mechanism rather than a problem of the heads themselves contacing platters.