Norton Utilities 15 needs activation after every re-boot

Two PCs, Win7x64, have Norton Utilities 15 installed. A couple of months ago, both copies suddenly lost their activation and needed the code to be entered when starting.  This has been fine with one PC - it continues to start correctly. The other PC needs the code to be entered every time it is started after re-booting. Then it is ok until after the next re-boot. 

 

What is causing it to forget that it is activated?

How can I make sure that it remains activated?

 

BTW v15 does what I want it to. I do not want v16 and all the hassle that comes with it!

Two PCs, Win7x64, have Norton Utilities 15 installed. A couple of months ago, both copies suddenly lost their activation and needed the code to be entered when starting.  This has been fine with one PC - it continues to start correctly. The other PC needs the code to be entered every time it is started after re-booting. Then it is ok until after the next re-boot. 

 

What is causing it to forget that it is activated?

How can I make sure that it remains activated?

 

BTW v15 does what I want it to. I do not want v16 and all the hassle that comes with it!

Thanks intesec

Norton Utilities 15 was bundled with Internet Security 3PC. The two products each have their own Product Key.

The label on the NU CD envelope says "Norton Utilities 15.0 1U 3PC  IN" which I take to mean one user, up to 3 PCs and no time limit.  Norton Utilities is not registered in my Norton Account, so I can't see any mechanism to manage any time limit.

 

I'll have a go at live chat support tomorrow.

 

Norton Support came up trumps. No wait to get connected to 1st line and it had to be passed up to 2nd line before it was fixed. All told, it took 3 hours to finally fix it.