How to update a standard vga graphics adaptor u need to read?

ok heres the thing my computer was recently a windows xp now i was a little younger about nine when we go it i could have played games like halo and grand-theft san Andrea's with a little glitches but hey it could have worked but that was before now my computer broke down because of a virus and my parent sent it to be fixed by a guy the guy upgraded to windows 7 i was ok with it until i tried to watch a movie the move was glitching and couldn't even play i was pissed out!!!! if thats not enough i tried to play a game and thats when i blew through the roof none of my games couldn't play so now i did some digging and this is my system information my rating is a 1.0 i have an turbo 4400+comb (k8m80-m7a and sempron 2800+) 1.60 GHz installed memory ram 1.50gb system typer 32bit operating system windows 7 ultimate i have 297 gb of space in all on the pc my disk type is an hitachi HDS721032CLA362 ATA DEVICE i dont know wat kind of graphics card i had before and my ocmputer was coustom built so i cant get any info and i dont know wher to find the guy who built it all i want to do is go back to playing games and having fun im tired of dealing with this somone pls help me please your my only hope pls