Microsoft recently released an update causing some trouble for Windows 7 users. On Patch Tuesday this month, the company released update KB3126446 to fix some security vulnerabilities. The patch was launched for Windows 7, Windows 8.1 and Windows Server 2012 R2, but apparently only gave Windows 7 users problems.
The vulnerability the update resolves would have allowed elevation of privilege if an authenticated attacker used Remote Desktop Protocol to log on to the target system. Microsoft sheds more light on the issue here.
In the Known Issues section of the support page for the update, Microsoft says, "You may have to restart the computer multiple times after you install this security update on a Windows 7-based computer that is running RDP 8.0."
Windows 7 machines that have been updated to Service Pack 1 in particular are impacted by the issue.
"Basically, what it could happen after installing the update is for your PC to reboot several times, but the number of restarts is not yet specified," explains Bogdan Popa at Softpedia. "But once this reboot loop comes to an end, you should be able to start re-using the computer normally, with no other issues likely to be caused by this update."
Microsoft runs down all available info about the security update for Remote Desktop display driver here.