Cause: Problem is because you have some virus in your computer or in external drive.
- Open Computer Explorer
- Click the Organise button located in the top left of the explorer and then click Folder and search options.
- Click view tab.
- Check Show hidden files and folders and uncheck Hide protected operating system files (recommended). Click Apply and then Ok button to apply changes.
- Now open external drive. You will find all your original files and folder hidden and also some unknown files. These unknown files are virus. Delete all unknown files and shortcuts folder. Now create a new folders and copy all original files and folder in this new folder. After you have copied all original files and folders in new folder, delete all hidden files and folder.
- Perform a full system scan to delete all virus.
- Restart your computer.
Your problem should be solved now.