Re-formating a HDD an starting over

[justG]

I'd have to respectfully disagree with Dave on this one. I'm also relatively new to the Mac, using a first-gen Mac Pro bought in late 2006. Since I download, evaluate and then delete so much software, OS X absolutely *does* accumulate application soap scum over time. I find a fresh install of the OS on occasion, followed by re-installing applications on an as-needed basis, makes a world of difference. (I like to call it recapturing that new computer smell.)

Long-time Mac users will insist from here to Sunday that a) Mac drives don't need defragmenting and b) taking the time to perform a clean install is a waste. I've never bothered with defrag, but in the latter case, I think they're just plain wrong.

[Edit] If you do decide to proceed with the clean install, you might find my method helpful. I have a 15GB partition on one of my drives. On it, I have a clean OS install + driver updates (peripherals) + software updates (Apple) + essential-to-me utilities (SuperDuper!, iPartition, etc.). When I want to do this fresh install thing, I just use SuperDuper! to clone that partition back to my main drive. I'm up and running in < 20 minutes.

Hope that helps!