I tried to;
1. Boot normally, no luck
2. Reboot into safe mode, no luck
3. Repair using my original (and legal copy) of XP PRO, no luck.
Ended up doing a format & clean install, luckily I am in a position of having everything that I need (not necessarily everything I want)
backed up on CD & DVD.
Sorry I wasn't able to find a good resolution for others who are having similar issues.
Good luck to you, and thankyou to everyone for your help & suggestions