Win7 Hibernates and sometimes doesn't Wake Up

Hello there guys, I recentely formatted my computer (yesterday, to be precise) but I have some kind of a problem I had before. My system starts the hibernation process after 30 minutes of inactivity and sometimes, like, if it's 4 or 5 hours (during night) without being activated, it simply doesn't wake up. It means my monitor display is black and cannot load. I have to reset it.

I'm using Windows 7 64 bits and my system specs are displayed on my profile. I would like to get your help in order to understand if it's some kinda serious or not. Thank you

Recreate the hibernation file type 'powercfg -h off' in an elevated command window. After that type 'powercfg -h on' and press enter. Reboot.
Hope it helps.

Hello there and thanks for your answer.
I will do that as soon as I get home since I'm not working on my laptop. In addition I would like to ask you what does it exactly do?

The command powercfg -h off' ? it disables hibernation. It also deletes the hibernation.sys file

You can also adjust the power options via start orb> type "power" .select power options and then customise your profile from there.

Hmm ok, I'll try it =D

It seems to work! Thanks both