Is it possible or even necessary to defragment my hard-drive on my Mac in the same way that i would on my PC. I don't even know whether it is needed but i know that it improved performance significatly on my IBM Compatible PC. Thanks in advance

It's possible. It's not very useful, or wasn't last time I bothered taking the time to do so. I went about a year with monthy defrags and didn't see any increase in performance, but that was on OS 9. OS X *might* be slightly more responsive to defragging, but I personally think it's a waste of time. p

Defragmenting is usually done about once a year, maybe less, depending on the use of the HD. If you are in graphics/audio, then it should probably be done once a month. However, a home user could get by doing it once every two years. As far as I know, no one has a free HD defrag utility. I think TechTools has one, I know Norton Utilities has a good one, but Disk Warrior is probably best. Side note: HFS and HFS+ partitions are more prone to fragmentation than UNIX partitions (UFS). With UFS defragmenting is essentially a waste of time, and is done by copying files from an old partition to a new one. K