Most sleep and hibernation problems can be fixed by doing the following:-
Open a command prompt as administrator.
At the command prompt, type powercfg.exe /hibernate off, and then press Enter.
Restart your system.
Now go back to command prompt (as admin).
At the command prompt, type powercfg.exe /hibernate on, and then press Enter. (that is a space between exe and /)
This should resolve the problem whereby a computer will not resume from sleep or hibernation.