Can we format vista installed PC with xp CD?

This is because you have a SCSI harddisk, which windows doesn't have the drivers for.

Download the SCSI drivers to a floppy disk.

When you boot on your windows xp cd, and get into the installation menu, then press F6 to enter a menu, where you can load your SCSI drivers from a floppy drive.

I had the same problem with my Compaq laptop. Are you trying to install XP with Vista via dual boot? Or do you want rid of Vista and install Win XP? Does the HP have a recovery partition?

What I did was made a recovery set off the recovery partition. Then used Vistas Drive manager to merge the drive into one partition. After that all I had to do was put the XP disk in reformat and install.

Make sure your BIOS sees the drive too.

- C

If SCSI isn't the problem, use Darik's Boot and Nuke to wipe the disc:
http://dban.sourceforge.net/

Create a DBAN boot floppy or CD.
Boot from it and wipe the disc.
Reinstall everything.

no scsi
no dual partition
want rid of Vista and install Win XP

Question is, can xp cd format the vista partition,
or xp and vista are on same file system, so difference

vista is already working but i dont want vista right now....

what disk do you have? look in the bios, it should tell you
then we can move on. If it 's SATA, you may need to load the sata drivers, when loading XP (use F6 key)

I believe if you want to simply get rid of Vista then you just install XP from your bootable CD and you will format and install XP overtop of Vista. First you should backup everything on that drive. remember that some of your programs installed on your computer that was backed up are Vista oriented programs and may not work on XP. You can go on-line and get the XP versions of most programs that are also available for Vista. Hope this helps.

If you're installing XP on a machine that came with Vista, you're not going to have all of the drivers needed for audio, video, etc. Compaq/HP doesn't provide XP drivers if the PC originally had Vista.