Downloading drivers for graphics card

Please keep your advices easy to understand as I don’t profess to know anything about the innards of my comp. Recently all my graphics have gone fuzzy and shot to pieces. (sorry that’s as technical as it gets) I phoned PC World’s tech. dept. and was told I need to download new drivers for graphics card, and that 3.5 megabyte should suffice. Well downloads.com could only offer about 1.5 mb. So I tried that, but it made no difference at all. What, or where else can I try?Please help!