Outlook office 2021 problem with Windows 11 computer account

Hi

just installed Office 2021 on my wife's PC 

Run Outlook classic and it will not run as it wants to use the pst and ost files on a second PC account she has but does not use. If I run as admin it opens with the old PC user ID and runs. 

I copied the pst and ost to the new uesr ID but still  refuses to run as it wats to use her old ID.

Any ideas gratefully recieved.