The boot selection failed because a required device is inaccessible

"The boot selection failed because a required device is inaccessible"... not the kind of message that brings a smile to one's face.

I had used Ubuntu loaded off a CD to resize my Windows 7 RC installation and shrink my Windows XP partition. When I rebooted I was greeted by this nasty message.

My Windows 7 partition would not boot at all and I had to go through a chkdsk boot check twice before I could get back into XP.

I managed to get Windows 7 back by putting the Windows 7 install disk back in and booting off it. After choosing my language, keyboard etc, the next screen let me do a repair. The Windows 7 repair took a little while and then told me it could fix it and wanted to reboot. After the reboot, I had Windows XP and Windows 7 (repaired) listed in my boot manager.

Phew. Remember, always back things up before playing with partitions and release candidate software!