I recently changed my PC's videocard.It now has GeForce GTX 460 SE (768 mb and second hand).However, I noticed that sometimes when I turn on the PC after it hasn't been turned on in a couple of days,my desktop freezes for 4-5 seconds without the issue being the PC "thinking" or processing anything.When this first appeared,I also rebooted the PC, and after the "Windows is shutting down" message, it rebooted, but stayed a couple of seconds longer on black screen than it usually does.I rebooted it several more times and the issue didn't appear.Any idea what these issues are caused by?They didn't appear before I changed the videocard.Are they fatal or they aren't anything serious?They happen very rarely.I also forgot to mention that I cleaned my PC with a can of compressed air 3 days ago, but I am pretty sure I haven't messed up anything in the hardware.