Please help me with video card issue!?

[Bluice]

Hi guys, I have an issue I need advice with please.

I have just recently upgraded the computer which is a 2.4ghz just so I could play Medieval 2! I have been stuck in Rome Total War for months now and I am obsessed with it. So I thought I'd get a 256MB ATI HIS X1550 (PCI only though as that is the only slot I had available) and upgrade the RAM to 1Gig from 512MB.

When I brought the computer home I realised the techie didn't even install the drivers so I spent 2-3 hours wondering why everything was crashing before I installed the driver. It makes me wonder if he had done anything on setups to alter the RAM settings....

Anyway, when I start the game it runs real smooth with no slowness and the intro movie is smooth and beautiful but then every time I load a battle or campaign map the little hourglass stops spinning and it seems to crash EVERY time. Someone please help me I am dying to play this game but I can't get it to work. Could it be an issue with a PCI card? It is ATI after all.

Any advice would be greatly appreciated, it also seems to crash not only on the game but even when I install it sometimes(I have successfully installed but a few times before I did I had to wipe it again and remove the Registry Key because the uninstall wasn't put on as the install didn't get to that point)

By the way it is XP, I just installed the new driver I didn't consider removing old drivers, I was under the impression it just replaced it. Could that be why it crashes all the time not only in the game but in the windows interface as well?

any1...?

EDIT: Maybe a long shot, but could installing a patch fix this problem?

Triple post merged ~sapi