You should be able to regain access by taking ownership of the files
. Right click the file, select Properties, then select the Security tab. Select the Advanced button, then select the Owner tab, chose Edit, then set the owner to your local Administrators group or to your username. Select OK to close out of the windows and the file should be accessible. If not, you may need to edit the permissions of the file
to add Administrators or your username to the permissions for the folder.