BleepingComputer.com: Windows Vista to Win XP help please

My hubbys computer came with Vista. Nothing but problems. Couldn't format and install XP so we installed Win 7. It installed fine, but did not take out Vista. Hard drive is 500gb. After installing Win 7, only 180 gb left showing.
found out if I disable the SATA controller I could install XP. Well I did that. XP booted up, formatted, etc, but keeps telling me that there is another OS on the same drive.
Now, I booted with DBAN. I guess it didn't work regarding wiping everything clean, but it did allow me to boot from XP.
XP is only showing 128gb hard drive. I now find out there are 4 partitions on this hard drive, but only one is showing up. I cannot boot into any other OS or partition.

I am at a loss. I really need to get XP into this computer and stop all the problems.

HP Pavillion a6000
Vista
pentium R Dual CPU E2220 @ 240 ghz
2gb ram
Hitachi HDP7250GLA360 ATA 465.76gb
NVIDIA Geoforce 7100 NForce 630i
Motherboard NVidia M\CP73 chipset
BIOS Phoenix V5.15


If I don't boot with XP I get a disk error screen.
I do not have a Vista CD
Do not have a Backup Restore CD
Have a Win 7 CD but not sure if it is a full version or not.
Have a Win XP Professional CD, older, no sp updates on it.
Cannot run any programs since i cannot get into the OS

Please help.

Thank you
Sherrie

You need at least Windows XP SP2 to see partitions more than 128GB.

ok, that makes sense.
But are you also telling me that XP without sp2 cannot format and see the whole 500gig hard drive??? So If I use Killdisk to boot up and wipe it completely clean, I will not be able to install XP anyway??? Or will I be able to partition the hard drive for XP on one partition and the other partitions for storage, like a cd or dvd or floppy?

I used to do this all the time for myself, friends, family with no problems, but things have changed so much just in the last few years that I don't understand any of it anymore.....

I have to do something though. I cannot get into his computer and the diagnostic said all 4 partitions had major error corruption.

So now what? help


EDIT: Booted up with Killdisk and it wiped the hard drive clean. Then booted with the Win 7 CD and it installed beautifully. Killdisk left all the drivers behind and no new drivers needed to be installed. The computer is now up and running.
PS: found the info on Killdisk on another part of the forum. Was using Dban and it just would not work. So downloaded Killdisk and it burned easily and booted perfectly! GOODBYE VISTA!!!! WooooHooooo!!!

Thanks!
Sherrie