I have two physical drives, C: with current Windows 7 (partially corrupted but still mostly working) and D: with an old install of Win 7 in who knows what condition. From current Windows I did a "Custom" install to Drive D: thinking it would over write everything on the drive. After a successful install (which cured my networking problem BTW) I find that everything that was on D: to start with is still there, and the drive is still D: even after booting to the new version of Windows. What happened? I also thought that whichever drive had the OS in use on it would become "C:", but I guess that wouldn't work too well in finding paths to software in a dual boot situation. Do I have to boot from a boot disk and format the drive before installing Windows? What would you experts here recommend?