It was booting from the boot.ini file in C:\windows\pss folder by default so I changed the file extension to disable it but it still shows 2 operating systems.
In recovery mode from OEM disk there is only 1 partition and 1 OS on C Drive. (D Drive is just a data disk)
The boot.ini folder in C Drive on top reads as follows after changing it per a post (which did stop the invalid boot error):
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /NoExecute=OptIn
On the boot tab in start up in msconfig it shows booting from:
multi(0)disk(0)rdisk(0)partition(1)WINDOWS="Microsoft Windows XP Proffessional" /fastdetect / NoExecute=Optin
and windows says the boot lines are all ok.
One option for boot up in the start up screen is "Microsoft Windows XP Proffessional" the other is just "Windows"
(This is a Asus p4p800 E Deluxe board with intel 3.0 chip and 2 IDE HDs and as a side note my Raid FastTrak controller says no bios is installed but it says it is working fine in devce manager also....?)
The machine still does fine although it seems a little slow....
I am sure someone knows the quick fix but I have spent allot of time reserching and can't find the cure.
Many Thanks for any nudge in the right direction....