It's a common problem, there are a lot of google hits, but I could found no working solution. When I leave my computer on and don't use it, and I come back, first only the cursor works, and if I right click, that freezes too. After 1-5 min it recovers by itself.
I disabled all power saving stuff, standby mode, hibernate, everything in task scheduler, and nothing yet worked. Please if anybody found something that is working, share it here! Thanks!