It could be the drive causing the performance problems, but if the drive is fairly active it can be a sign of two things: either you don't have enough RAM in your computer or the drive is dying (or both). Once your system consumes all of the physical RAM, it uses space on your HDD to create "virtual memory". What that means is a portion of the disk is used to fool your computer into thinking it's actually a part of the physical memory installed so that it can carry on operating. The problem is that HDD access is far, far slower than accessing physical RAM. This itself can cause a significant performance decrease.
An easy way to tell if you don't have enough RAM is to open Task Manager and look at the amount of memory that's being used. In your case, if that number is going over 1GB, then you know you also don't have enough RAM.
However, for now, your main concern should be protecting your data and getting ready to replace your drive. I've had clicking drives in the past and they really don't tend to last very long. The only way to backup everything properly is to make a list beforehand. Don't wait for anything to get worse. The faster you get on top of it, the less chance there is of you losing something important.
2Nobody can tell you if in your specific case faulty hard disk is the reason for PC slowness, however faulty hard disk can make whole computer freeze and generally behave slower. On a related note, clicking noise is usually a sign of an imminent failure. Time to check that your backups are current and good. – haimg – 2012-02-22T15:51:39.650
Well yea, ok taking a general scenario. Can this be reason of slow computer behaviour ? – aibk01 – 2012-02-22T15:54:43.937