Oxford Ankle BootsyellowDec 28, 03:43 PMCan re-installing the OS too many times on a imac g5 , add wear and tear to the HARDDRIVE? Yes it adds wear and tear, but not in any amount that would make any real difference to you. I wouldn't worry about it. also, when you erase and re-install your OS does it take from the amount of GIG space, versus just leaving it alone and deleteing all the files