If you experience random crashes on Windows Server 2008 R2, you may have a problem with the DEP (Data execution protection).
On Windows 2008 R2 there seems to be a problem with DEP. We have seen the crashes stops if users disable it for the gui.exe process or entirely. Often the crashes are logged by the Windows Event Log. According to the log they stem from random DLL files with no association with the PDF printer.
Here is how to disable it:
Open Control Panel, click on System and Security→ System → Advanced system settings. In the Advanced tab, click on the Settings button in the Performance section (the first one). In Performance Options, Data Execution Prevention has its own tab.
The odd thing about this finding is that has only been seen on Windows Server 2008 R2. Earlier or later versions of Windows Server has not shown this problem.