The hibernation was set with the power configuration and was OK before. It is still there and works at the set time, but is disappeared from the Shut down links on the start menu, all the other options remaining. It disappeared also from the shut down menu called with Alt-F4. If I use the hibernation key on the keyboard it behaves OK. However, if I use either the sleep key on the keyboard or the option on the start menu, it sometimes behaves correctly while other times it does go into sleep, but awakes back immediately by itself, in less than two seconds.Furthermore, waking up from hibernation takes a very long time. All goes well when the computer starts, but when Resuming Windows appears is slows down, and we can see the little balls moving very slowly followed by the Windows log shrinking and expanding extremely slowly. It can take five minutes to wake up. I tried to use the upgrade OS installation option over the existent one (it took about twice the time as for a clean install). Nothing changed. Also, I tried the command line powercfg –h and I received the answer Invalid Parameters -- try "/?" for help . The help says it is correct, but it is not accepted. What can this be? Any suggestion to solve this problem would be welcome, thank you.