Freeze during loading graphics switch from on board to card

i have a dell p4 and im tryin to switch from on board graphics to a graphics card via normal slots in pc. i cannot get past the load page it just freeze about 3 secs into the loading bar, same happens with live cd and 8.4. on a rare occation 8.4 asks me to use low graphics mode or configure.. if i configure i cant test or continue. also windows xp freezes as well during load.

i can only boot while using onboard graphics which are pretty useless for 3d imaging and animation...

this is currently happening with 2 separate graphics cards and i am stumped. Any help is greatly appreciated.

graphics cards
s3 virge gx
and the other is a 1996 matrox something lol.

i am a new user of ubuntu and have been using only about a month now so if code is involve please specify.

Thanx Much!!!