Hello,
What version of SEP 11.x are you running? OR Are you running SEP 12.1 ?
What OS are is this issue occurying on?
Could you upload us the SEP_Inst.log from %temp%?
Also, try the steps below:
- Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\SMC
- Select and right click SMC and choose Permission from the drop down menu
- In permissions add the User, Administrator and SYSTEM with full permission
- Reboot the machine
Try again installing SEP.
Hope that helps!!