Microsoft have done it again – an update the creates a BSOD error “Stop 0x50 in Win32k.sys” (image below)
http://www.techtimes.com/articles/13391/20140820/bsod-gives-microsoft-blues-faulty-patch-tuesday-update-yanked.htm
The fix is relatively simple. Boot into the receovery partition, or another partition such as an install disk, open a command prompt and run
del %windir%\system32\fntcache.dat
More info on Microsoft’s KB article: http://support.microsoft.com/kb/2982791