Hardrive problem :(

ok i bought a new hardrive it works great but when i copy something 

and try to play games or run photoshop they just wont run until copying is done ? 

any ideas why is it happening ? 

is it your only HD? looks like copying takes alot of system resources, enough that your system stalls.

are you on vista? vista had that problem.

nope im on windows 7 and i dont think my system resources are less