1) Right click on the drive. Choose Properties.
2 Click on the Security
3 Click on the button Advanced.
4 Click on the Users in the permission entries section.
5 Click on Change permissions.
6 Now again click on the Users in the permission entries section.
7 Click on the button Edit.
8 Give it full control right, and check the box Only apply these permissions to objects and/or containers within this container only.
9 Click on OK to close on the dialogs.
I suggest you to recover your files first then do any thing on this drive.There are many free data recovery software available in the market.