Manual Activation Key not working

I recently acquired a new work PC and I had to re-install Creo Elements 8.0 (free version)

On my old PC I did not have to use the Manual Activation, it would just load up straight away but for some reason that is no longer the case!

Now it does not find internet connection and when I then use the Manual Activation Key I get the following error message;

“The activation check for Modeling Express

to run on this machine failed because of the

following reason:

The activation code you entered is invalid.”

I have copied and pasted several different codes but all come back with same error message!

Can you please help as I regularly use this software?

Rob