Supa Beanie
I'm horrible at explaining these things but I will do my best. (I'm not sure how it works in linux) but when you start your computer in windows you can press f2 to enter the bios setting at the start of the computer. You have to specify your CD-ROM as the primary boot device BEFORE C: or A:
After you've done that make sure you save your BIOS settings and restart your machine with the disk in the drive.
This has nothing to do with Windows. You may want to inform yourself what a
BIOS is before making claims.
Also, the key to get into it varies. For most boards i've seen it's DEL. Usually the key is displayed on screen upon startup (For example "Press DEL to enter BIOS" ).
Edit: Also, "A:" is not a device, "A:" is a drive letter, used in Windows to mark a volume (there can be more than one volume on a physical device, though i only know about HDDs using that).
The BIOS only knows hardware devices, that is floppy disks, optical drives, HDDs, etc.
It calls the device that was specified as boot medium and this will then start the boot loader, if available. The boatloader then will start the OS.
Edit2: stupid parser making smiley's out of quotation mark + right parenthesis ...
Supa Beanie
When you go to enter the BIOS don't leave the disk in the drive, wait until you set it to boot from CD-ROM and then put your disk in the drive.
The BIOS doesn't care if there is a disk in the optical drive.
PacJack360
Yuki The Uke
@OP: windows after linux is a bit odd. If you still have your ubuntu install disk, boot from it. Use gparted to wipe the disk into free space, and then it will boot the vista disk.
also, UPDAET LIKE ALOT, KAY?
I take it that you didn't notice the necro-ing
This is a necro? ********...