Posted 13 February 2009 - 05:46 PM
<<Is it possible to dual-boot XP from drive #1 and Win7 from drive #3?>>
Yes, it is.
When you install the Win 7 beta, it will employ its own set of boot files, which will override your XP files. The result is that Windows 7 will become your default install, with XP being just above it on the screen and referred to "previous Windows install" or something similar.
When the boot screen comes up, all you do is move the pointer 1 line up if you want to boot into XP.
If you want to boot into XP as the default...not sure you can do that. I suspect you can by editing the Windows 7 boot files but I was never able to get into my Win 7 install, so I had no chance to try that.
FWIW: You may be interested in EasyBCD, the program I used to eliminate the Windows 7 boot files after I gave up trying to install Windows 7 properly.
<<Or would I have to change the BIOS each reboot in order to move drive #1 or #3 to the top of the boot list in order to boot from that drive (assuming that's even possible)?>>
The BIOS won't matter, it only sets the boot order for XP...the Windows 7 bootloader will reflect both the XP and the Windows 7 boot options.