Endpoint Protection

I wish to change some settings in the Sep Client. However, even when I use an Administrator Windows account and try to change the SEP Client settings, i get a message that says "Your administrator has locked this feature".I cant update 

The SEP Clients are standalone (ie. no central SEPM server is managing them),

Sounds like they were managed at one point and then made unmanaged or someone exported a managed client install for what was supposed to be an unmanaged client. Long story short is that you'll just need to re-install the client with the unmanaged version.

I Try this registry change
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\LiveUpdate

AllowManualLiveUpdate 0- means liveupdate button will be greyed out. 1-means it will be available to click.

but I received the notice"Cannot edit manuall liveupdate:Erorr writing the values new contents"

I am using SEP 14 and cannot update. The other machines in the group all update normally

Disable tamper protection first, assuming the option is not locked.

Your solution is excellent 

thank ℬrίαη

You're welcome.

We will require more details - did you get any error message when you try to update? Have you tried rebooting the PC and trying again?

Do come back with the details and we'll try to help you.

thankTony Sutton!

I  already overcome it

That's great to know, thanks for letting us know.