Restoring old file manager

[novel hemlock]

I installed the files app and set it to default. All's fine and well but it was slow for me. So I unchecked the set to default option and uninstalled the app. Now the windows file manager app is saying not found. I ran the registry file to restore file manager but it doesn't work correctly. It only works when a new window is open. I cannot open any folders at all.

Also, I cannot reset my pc because I need it for work and cannot afford to waste time on setting it all up again and backing up stuff

Update: Installing the files app again, and disabling the default manager setting fixed the issue