Do you have the problem of "Turn off the Display" options in the Power Settings changing from... the setting of "Never" to "20 Minutes". Well, I did and it would affect my Windows 7 & 8 machines (have not tested on Vista or XP). I finally ran accross the fix for me and a few others. I would like to thank & give credit to "vanowm' over at Windows 7 Forums for the post, in this thread('Turn off the display' resets itself to 20 minutes instead of Never!), from May 28, 2011. And, "joshmon" posted this in the same thread... As I had been using the free version (2.55); and, this may be fixed in the more recent versions of the paid or trialware, which I haven't tested. This is in no way a put down of HDTune, it is a nice little app and I appreciate the free to use version. I just never even realized the correlation between the power option changing and using HDTune 2.55 until I read that post and tested it. If this has been posted before apologies, as I did not see one on a search of the forum.