My dad also has 2 WinXP's
If the first WinXP is on the first partiton and the 2nd on another partition you have to format one of them. Say WindowsXP1 is on C:/ and WindowsXP2 is on d:/ and you want to get rid of WindowsXP2: just boot WindowsXP1, get in DOS and type 'format d:'.
It should work fine, but you loose all data on d:/
If this doesn't work you can download Partition Magic or some other partitioning app and make some boot disks and try formatting from there.
After formatting one of the partition you probably have to reconfigure your boot.ini file, unless the second Windows has dissapeard from your boot menu.
The boot.ini file is located on the drive where Windows is installed and it looks like this:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="WINDOWS1" /fastdetect
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="WINDOWS2" /fastdetect
Open the boot.ini file with notepad and delete the following line(s) (assuming the Windows you removed was on that partition)
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="WINDOWS2" /fastdetect
Save it and reboot, the bootmenu shouldn't popup anymore. If it still does, remove the following line(s) also:
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="WINDOWS1" /fastdetect
Ask me for more info!
(don't know how to do it with 2 windows on 1 partition, think it doesn't work)
Please correct me if I'm wrong guys.