Blue Screen Error HDD Related

Hi,
i get the Blue Screen error a lot, it says:
DRIVER_IRQL_NOT_LESS_OR_EQUAL with error number 000000D1 or 0000000A
and nvata.sys, i searched up and some website said that the error nvata.sys refers to an error with the hard drive.

I have 2 hard drive, Western Digital ( old one ) and Hitachi ( new one ),
the problem occurs when:
1-Playing World of WarCraft which is installed on partition H ( old hard ).
2-Copying the World of WarCraft folder to the new hard.
3-Defragmenting partition H.

I've updated the driver, and also tried connect the old hard to another sata connetion but still have the problem.

Thanx...