All computers that you buy from a store seem like they always have something wrong with them either overclocking,"Blue Screen Of Death,ETC the best way to get your moneys worth is to just build your own pc 
I just did ! A rather tasty box :-)
2 160 GIG SATA HD's , 2 GIG of RAM , blah , blah , blah .... cost me a packet !
It's worked for about an hour :-(
Mega problem's , don't like my RAID array , don't like lousy Nvidea drivers, BIOS is all wrong,needed upgrading, you name it it's all wrong :-(
Many hour's later , it's just workin !
Just ......
Gone back to my Mac Mini and old but happy FreeBSD lapper :-)
The tasty new box lies gathering dust , till I have time to sort it !