After installing Symantec Endpoint Protection (SEP) on a Windows 8, 8.1, 2012, or 2012 R2 system; the system hangs randomly.
NTFS hangs during disk I/O.
Windows 8, 8.1, 2012, or 2012 R2
Install the following Microsoft hotfix:
https://support.microsoft.com/en-us/kb/2904100