Windows 7 will always boot to drive letter C: in multiboot configurations.
When configuring a Multi-boot configuration using Windows operating systems, you need to install Windows Versions oldest to newest on separate partitions. In doing so, Windows 7 is going to be installed to Drive D: or E: or such. In all previous versions of Windows, if you have a multi-boot configuration, the drive letter for that OS is always the same as the drive where it was installed.
Windows 7 does things a bit differently. EXAMPLE: I have 3 partitions on my hard drive. C:, D: and E:. XP on C: Vista on D: Windows 7 on E: When I boot to XP, the boot drive letter is C: When I boot to Vista, the boot drive letter is D: (Simple) Well, I learned the hard way that when you boot to Windows 7 from a partition other than C:, it will show the boot drive as C: in Windows 7 (It swaps drive letters with the boot drive and C: transparently). When you boot to the other partitons, the drive letters are as they should be and the change is only effective while booted to the Windows 7 Partition.
on Dec 03, 2009 | Computers & Internet