>>It is registered in RunServices<<
According to Microsoft KB RunServices does not work on NT/2K/XP/2K3. What is going on here?
>>How would you go about booting XP in safe mode?<<
I think you enter "safe mode" by pressing F8 before Windows starts.
>>and it disallows any other programs from starting (including the start menu and the windows task manager [on winXP]) <<
Can I ask how it does this?
>>Is there any other way aside from luckily finding the password around my program that you can think of? <<
If you have another xp computer handy:
taskkill /s yourpc /u administrator /im yourprogram.exe
You can also edit the registry remotely.
...but you'll need the administrator password. Come to think of it, without an administrator level password your computer is useless. You'll need to reformat and start again sooner or later anyway. (Or hack the computer to gain system or admin priviliges.)
There is also a backup of the HKLM hive that is created when you first install windows but you'd need to reinstall all your programs. However, your settings, in HKCU, would remain.