We are seeing the same issues ever since moving to LANDesk 9.6. The problem only seems to occur after we install patches, prompt users to reboot and after the restart happens. If we go to the local or network printer, right click on it and select printer properties we will get a message that states the printer driver is not install on this computer. If we click "Yes" to install the driver now we then just select the driver and printing works again. We haven't been able to replicate the issue on a machine without LANDesk so we are pretty sure at this point it is not a windows update but something caused by LANDesk 9.6. This would surprise me as LANDesk 9.6 also causes an issue with protected view on Windows 8.1 64bit with Office 2013 32bit. The protected view issue doesn't seem to be a problem with LANDesk 9.6 SP1 so we are now trying to verify that the print driver issue is also resolved with SP1.
Edit: We do not install Endpoint Security.