Possible Duplicate: How can I reinstall Windows 7 if I lost my installation DVD? I need to reformat my computer, but I don't have my OS discs with me (I do have the cd keys, though). Can I burn a pirated copy of the OS, and then install using my legit cd keys? Answer There's no need to pirate; you can download the ISOs for Windows 7 installation media directly from Microsoft (well, okay, Digital River's hosting the download but whatever), free of charge. 32-bit Windows 7 Home Premium 64-bit Windows 7 Home Premium 32-bit Windows 7 Professional 64-bit Windows 7 Professional Links taken from here . I can't personally confirm they're live, but I've done this in the past and they look the same as I remember. EDIT: Removed Ultimate links since they appear to be dead, but they're out there. Somebody feel free to comment and/or edit these in.