Once a day would be retarded yes, you'd probably destroy your hard drives from all the reading and writing needed to be done. I do it about once every 6 months, sometimes longer. There are certain exceptions though, if I go from nvidia to ATI or vise versa I reformat because of weird driver issues that can occur. Otherwise screw it, backing up my 200 gigs of **** onto dvds setiously blows, I guess I could put it on one and format the other but I never bother. There should also be a poll on defragging, I defrag about once every month or two since I'm lazy and it takes FOREVER to defrag all my stuff.