Administrator control please?

Good morning everybody. Looking for some help please.

I have recently Installed a new Replacement Hard Drive with a new Windows 10 Installation.

However, now when trying re-Install my games which iv'e played In the past without any problems

I Am being told "An Administrator has blocked you from runnung this app Contact the Administrator"

I thought I had always been the Administrator!!!

Can you please advise me the best way to get back full Administrator Control of my Computer.

Many thanks