I just did a new install of win7 on a brand new out of the box 840 evo 250gb. Now the OS seizes up quite a few times a day; sometimes even during idling my box will just hang. Is there something obvious that I missed, or did I get a lemon?
Have you checked your event logs? Could be related to buggy power management. Same thing used to happen with my Crucial M4 drive until I updated the firmware and the problem went away.