Sorry, I didn’t read you question properly
If you have changed to a different Windows computer, strangely the project folder may still be set to the user account of the previous machine.
You will need to remove the account settings or give the new account permissions.
Now, I think you can (a bit convoluted):
right-click on the project folder
select ‘Properties’ at the bottom
click the third tab ‘Security’
click ‘Edit’, under the first box on the right
Another popup will appear
the top box will say something like:
type in your username into the box and click ‘Check Names’
Keep clicking okay to make the three boxes go away.
The project should now be okay.