file explorer

Hello, I imagine you have a permissions problem.

Try Tweaking.com's repair tool (free), only use the repairs you need- it includes several related to permissions. Observe its recommendations as to caution.

And when all is well, if you haven't yet done so, start creating disk images routinely, which will often help you recover from problems quickly without tech help. (E.g. Macrium Reflect free is often recommended here).