I have successfully installed W7 on a new hdd to dual boot with XP. However, I seem to have a problem with drive letters. On my original disk I have two partitions: Drive C has XP and Drive Z has all my apps and files. I formatted the second disk with one partition (drive E) and left the rest unallocated. I've installed W7 on drive E and all shows up correctly in my computer when I boot into XP but if I boot into W7, drive E shows as C and drive Z shows as D. Drive C doesn't appear at all. I can change the drive letter of D back to Z but because C is the os partition it won't let me change it. Help anyone.