Installing Debian Lenny on Windows Virtual PC
Create a new Virtual Machine, put the Debian Lenny CD in the drive, boot the machine. It should boot from the CD. At the Install prompt press TAB to edit the Install command.
Just before the vga= argument add a noreplace-paravirt argument, then change vga=normal to vga=791. Then press Enter to boot.
I got these instructions from http://wiki.debian.org/MicrosoftVirtualPc2007/lenny
You’ll need to make the same change to the grub configuration / launch string after installation. Press ‘e’ to edit the boot command, edit the kernel boot and add those options, then press ‘b’ to boot. That will get you to the first boot, then edit /boot/grub/menu.lst and add those options to the kopt= line, remember you don’t have to uncomment that line! Then run update-grub to update grub and reboot to check your work.