Assuming you have XP, Go to Control Panel>Performance&Maintenance>System>Click the "hardware" tab>Device Manager>Find what you're looking for on the provided list> Right click on it>then click "Properties >and then the "drivers" tab. One option shown is "Roll back driver"
Personally, I think your hdd is crapping on you but I've been wrong before.
Defragging isn't going to do much good being as you just re-formatted and it shouldn't need defragging.
has some freeware utilities that can help you check your hdd health. It'd be worth checking out if all else fails.
Look under "Drive Utilities". The freeware is mixed with shareware so make sure of what you're downloading.
One diagnostic for Maxtor that is free is Here
Hope this helps!