I reformat once a month on my old PC (Pentium 3 1.3GHz, 128MB SDRAM, GeForce 4 MX440 PCI 64MB) because it slows down massively. It is an E-Machines and using those discs, reformatting takes 7-8 minutes, and another 5 to go through all the BS setup info and things. After that, to install everything takes maybe 30 minutes tops, including drivers and so on. Installing big games can take a bit of time, but generally, I have it back to where it was except running better in an hour or two.