I've had the same problem on two computers.  When the operating system is new and there aren't many other programs installed, hibernate works well.  Long before  I've loaded all the programs I want to use, hibernate stops working.  The Microsoft help website says that many programs are incompatible with hibernate but doesn't offer much   real help.    

   I have had this same problem with my laptop which is hooked into a router with my desktop computer.  I tried several things to keep it from waking up and the only thing that worked was unplugging its network cable.  Evidently, something coming from my desktop computer or from the internet was waking it up.

Here is a solution sent to me by Jon Davis


I had this same problem with my pc – I’d hibernate it overnight only to find it running the next morning having woken up on its own at random times overnight. Network connectors and modems have the capability to wake up the system on network activity when it’s in the hibernation mode ( S4 state ). To fix this, you need to use the device manager to access the Network connector ( XP: Right click My Computer / Manage/Device Manager/Network adapters /<select your adapter>/Details tab). Click on the drop down and browse to see if S4 detection is enabled. You’re looking for a property that says something like “Wake on S4” or “Wake on network activity” – the precise wording depends on the manufacturer and not all network adapters have this property. However, judging from your symptoms, yours probably does. It should be obvious when you see it and it’s probably set to true. In that case, reset it to false and save. Repeat this for each adapter you find and also repeat this for any modems you find.  This should solve your problem and your need to remove that network cable when you hibernate. While this is a harmless change and should be easily reversible if something doesn’t work with the adapte afterwards, as always before changing your system configuration, you’d do well to save the current configuration before you start this procedure. – and always copy down any field you change so that you have a record to restore it with if necessary. Good luck.

   The Details tab on my Network Adaptor was not editable.  But I did find on the Power Management tab a checkbox called "Allow this device to bring the computer out of standby".  I will see if that works.