I have recently replaced my hard drive, the new hard drive i replaced it with is the 'Hitachi HDS721010DLE630 ATA Device'. I have recently started having random restarts without notice, and wondered if this is the cause of the problem as i have not had any software to install it, however as far as i am aware you do not need to install it by using a disk. Also when i troubleshoot problems with my computer i am getting 'hardware changes might not have been detected'. Any information that could help solve, or if this is not the cause of the restarts would be appreciated. Thanks.