I no that I ment to say mac compatible. Some drives dont work with macs. If u have a power mac u should jsut be able to open the tower and put it in. I dont know if there is two hardrive slots in your mac. But if you have to take out the hardrive already in the tower DONT. If you do everything will be lost. Unless you have an external drive to save everything on to, but since I doubt u do I would recommend to bring it in to a mac certafied store to put in the new hardrive. (Voids warranty if you dont) And the will be able to save the hardrive contents and put them on the new hardrive.
SMILE, its the second best thing you can do with ur mouth