"I dont want to format it cos there is all my files on there
That's why you should always keep your files backed up on a second drive, in case the drive fails.
All hard drives fail eventually no matter how much you look after them.
Test it with "WD Data Lifeguard Diagnostic for Windows":
Select your hard drive on this page, then click "Available software
" under the drive model: http://support.wdc.com/product/download.asp?lang=en