BSOD - irregular, every couple of weeks, atiksmdag.sys?

Hey guys,

Built a PC for my boss. Sadly has been plagued by this issue where BSOD then screen goes black every few weeks. At which point it won't respond until you turn it off and on again. The minidump file I read suggested it was an atikmdag.sys thingo, which supposedly has something to do with the ATI graphics card in some way.

Any help would be massively appreciated. Have tried updating graphics drivers already.