My display flickers and is garbled, HELP!

I have a Sony Vaio laptop computer. the model # is pcg-grx560. i got it about 3 years ago. it is a windows xp.
ok here's my problem. when i try to play 'the sims 2' or any dvd in the laptop, the screen flickers. this just started happening about a month ago, but it wasn't as bad. when i first put in a dvd the screen was showing a whole bunch of red and green dots and little squares all over. then sometimes when i play sims 2 little white dots would flicker on the screen. also when i scroll down internet explorer sometimes, the screen flickers.(like a whole bunch of horizontal lines flashing) just today, i tried to play sims2 and the whole screen was flickering so bad i couldn't even see, it was all garbled too. like when it happened before it was only a tiny bit and only lasted a couple seconds. but today i put the cd in and the whole screen was just totally garbled. even after i took the cd out and when back to the start menu the whole screen was garbled. this lasts until i turn off the computer. this is the worst its been and i have no idea what is the matter. i don't know if the display settings are wrong or if i just need to uninstall something or what. if anyone has any ideas PLEASE HELP ME!!!!!
i don't think its the programs or the dvd's because they worked absolutely fine a month and a half ago. this just started recently.
the only thing i installed was an anti-virus program called eztrust antivirus. i don't think this is the problem though because its on my other puter and it works fine.
any help would be appreciated.
brittani

ps- the display settings are 1280 x 1024 pixels, and highest(32bit) color. the display is: 1. sony notebook LCD on Mobility Radeon 7500
If you need anything else let me know.