Another stupid o2 / buldozer problem

[Master_Chief]

I have buldozer installed in c:\ofpmod\o2_viewer_upd\
and o2 is installed in c:\ofpmod\o2light\. I know the
instructions say to install it on a base drive, but this worked
anyways. Its been working well for over a year now, but
then a month ago I started up buldozer, and it said 'please
insert correct CD" So i made a backup of it and re-downloaded
in from the breathe site. This time it started without the
insert CD message, but everytime it updates from 02 it locks
up. it doesn't CTD or give a message, it just locks up my
entire system, except that the mouse can move and the
keyboard can do a ctrl-alt-del, but usually shortly after it
crashes completely. So my question is, what could be
causing this? i didn't change any system settings and i don't
have a virus. it just stopped working. Can someone tell me
what system drivers are used when buldozer uses textures?
btw i use a tnt2 model 64 nvidia card, which is old but it never
had trouble running o2 and ofp. any help would be great
btw here is what i tried so far:

used the original insert cd version with the cd and it still crashes
installed o2 and buldozer on base drive d:\ same effect
restored original data\ and data3d\ dirs same effect

*edit* i removed the regestry keys and reinstalled o2 and it
works perfectly now

[Crowley]

You do have a legal copy of OFP right?

[Master_Chief]

yep. I bought the ofp gold upgrade pack and then resistance.