I decided to add Xp to my existing vista system, followed the steps
1) Partitioned a new space on the hard drive (d
2) Installed XP
3) XP initiated a restart

And then it all went wrong.

Neither XP or Vista will load, and normal start up jumps to "A disk read error occured press ctrl+alt+del to reboot"
The same issues reoccurs what ever route I follow to resolve this, be it vistas install disk repair function (which occasionally lies to me, telling me I have a camera or mp3 player attached, and refuses to run) Fixboot commands in the XP repair console, and going through the steps listed here Windows Vista no longer starts after you install an earlier version of the Windows operating system in a dual-boot configuration i.e. done from the command prompts in vista repair.

" 1. Use Bootsect.exe to restore the Windows Vista MBR and the boot code that transfers control to the Windows Boot Manager program. To do this, type the following command at a command prompt: Drive:\boot\Bootsect.exe /NT60 All

In this command, Drive is the drive where the Windows Vista installation media is located.

Note The boot folder for this step is on the DVD drive.
2. Use Bcdedit.exe to manually create an entry in the BCD Boot.ini file for the earlier version of the Windows operating system. To do this, type the following commands at a command prompt.

Note In these commands, Drive is the drive where Windows Vista is installed.
* Drive:\Windows\system32\Bcdedit /create {ntldr} /d "Description for earlier Windows version"

Note In this command, Description for earlier Windows version can be any text that you want. For example, Description for earlier Windows version can be "Windows XP" or "Windows Server 2003".
* Drive:\Windows\system32\Bcdedit /set {ntldr} device partition=x:

Note In this command, x: is the drive letter for the active partition.
* Drive:\Windows\system32\Bcdedit /set {ntldr} path \ntldr
* Drive:\Windows\system32\Bcdedit /displayorder {ntldr} /addlast
3. Restart the computer."

Nothing seems to have worked so far.
Any ideas? I'd like both OS running, but would be more than happy to have just one of the two (Vista for preference) back up and working.

Data not backed up, but nothing valuable would be lost.

Thanks in advance.

do a full restore from the hidden restore partition (read your manual on how to do this) or use the supplied restore discs that came with the computer.This should put the computer back to the original new condition. It may or may not re do the partition...all depends on what type of restore application is used.