"[blue]when i boot there is a ticking noise inside the case[/blue]"
Inside the case of the PC or the hard drive? Assuming you have narrowed down the noise to the hard drive, then the next question is how long it's been happening and whether there was a time when it didn't exist.
Like mainegeek said, if the noise is relatively new or annoyingly loud, then there's a good chance that the drive is about to fail. Make sure you take the necessary precaution in making a complete image of your hard drive to CD, DVD, tape drive, or another HDD.
"Some" ticking noise at low decibels is common. What you are hearing is the resonance of air being pushed around at high speeds on the inner portion of the case as the head moves back and forth. The more a drive is fragmented, the more the head has to move especially at bootup. Try defragmenting only after you backup your data.
There are also other possibilites to the cause. Sometimes when the lubricant around the head wears down, there is less air resistance to hold the head slightly above the disk platters. As soon as random contact is made, you start losing sectors and eventually the whole drive (not to mention hearing more grinding noises in the process).
~cdogg
[tab]"All paid jobs absorb and degrade the mind"
[tab][tab]- Aristotle