All modern cards support OpenGL, sicne OpenGL and direct X are teh main standards now days, although Direct X is more popular. Things like Glide3D and such are now long gone, people who have old Voodoo2 chip based graphic cards, and probably voodoo3\'s would have problems since they wouldnt support OpenGL (well my old computers card never did, then again Voodoo is no longer in buisness).
Id suggest upgradeing to at least a 32meg card either a Geforce or a a Raedeon(sp?) since they support OpenGL. Card costs are coming down all the time, and with the release of cards like the geForce4, the older cards will become even cheper than they curently are.
Safe mode runs useing software mode, ie. your CPU does all teh graphical work, and if you havent got a fast CPU (im talking about at least a 800mhz) then you will get crap framerate in this demo.
If you install new video drivers and end up having to reformate yoru HD you have a major problem with your machine, or you dont realy know what your doing ^^...