Starting situation is an installation of Windows XP and Fedora 9 on the hard drive. The goal is to start Windows from Linux with the KVM virtualization solution. First step is to create a second hardware profile inside windows, this is necessary because windows should be bootable from the virtual machine and native hardware. Then it is time to try the first boot with the command line:
qemu-kvm -std-vga -m 512 -hda /dev/sda
This ends in the error message:
A disk read error occurred
Press Ctrl+Alt+Del to restart
The message is printed by windows boot loader which is installed inside the boot sector section of the windows partition. This error gives the suggestion that there is something wrong with the boot loader. There exists a project which provides a CD to fix the NT bootloader and to boot into installed windows versions without the bootloader on the disk. With the following command line it is now possible to boot windows:
qemu-kvm -std-vga -m 512 -hda /dev/sda -cdrom fixntldr.iso -boot d
This solution works without changing the windows boot loader and doesn’t destroy the native boot.