Unable to install SEP 12.1 on Window server 2003 R2. “Symantec Endpoint Protection has detected that there are pending system changes that require a reboot. Please reboot the system and rerun the installation.”

I've tried to install SEP 12.1 on my window server 2003 R2 server but failed. the error “Symantec Endpoint Protection has detected that there are pending system changes that require a reboot. Please reboot the system and rerun the installation.” pops up.

I tried troubleshoot by following the guide in this link:

http://www.symantec.com/connect/forums/sep-121-will-not-install-detected-system-changes-requiring-reboot

http://service1.symantec.com/SUPPORT/ent-security.nsf/ppfdocs/2007121609023348?Open&dtype=corp&src=&seg=&om=1&om_out=prod

I remove the registry, and try to install without reboot. The same error came out.

I try it again by removing the registry and reboot. Same result.

The Installation log is attached.