I have a dual boot system with windows XP on one drive
and Debian "Lenny"on the second drive. I use the entire hard drive for the debian install. I decided to upgrade to "Squeeze" this weekend. The install went well until I got to the Grub installation. I received a message saying that "A step failed", continue and try another option. I elected to "finish the install" without Grub2. everything continued to go accordingly until it was time to boot into the new system. I was able to boot into Squeeze, but not back into windows. Does something have to be changed in the /etc/grub/menu.lst.? This has proven to be somewhat of a challenge and I sure could use some feedback here.

Thanks for listening
rickolai

Assuming, and it sounds the case, that grub2 is now installed, but Windows wasn't automatically added to your grub list, it should be fairly simple to fix.

First, make sure you have os-prober installed. (Both of these as root.)
Then update grub.cfg
And it should autodetect your windows install and add an entry to your boot screen. If not post back. We'll need to gather some more info.