To make hibernation unavailable in Windows 7, follow these steps:
- Click Start, and then type cmd in the Start Search box.
- In the search results list, right-click Command Prompt, and then click Run as Administrator.
- When you are prompted by User Account Control, click Continue.
- At the command prompt, type powercfg.exe /hibernate off, and then press Enter.
I used these steps to free up about 15gb of space on my c drive!
Chances are you installed a windows update to your server that caused this to occur. There was some in April and May 2016 time frame that were released.
Completing the post installation tasks will resolve the issue:
Microsoft Warns WSUS Users About Flawed KB3148812 Update