Welcome to the community, sandyloggs!
I'm sorry to hear about your WD external HDD.
I'd recommend you to try connecting the drive to another computer and see if your files will be accessible there. Another thing you can try is using another anti-virus software and scan your external again.
You can give some third-party data recovery tools a try as well and see they can make your data visible, unfortunately, nobody can determine how successful that attempt would be. (
http://www.tomshardware.co.uk/forum/291895-32-best-data-recovery-software )
Either way, I'd strongly recommend you to test the HDD's health using WD's Data LifeGuard Diagnostics by running both the quick and extended test. The tool also gives you the option to fully erase your external HDD by writing zeros on the HDD sectors. This, however, would erase all the data on the external to the point of no return, so I'd suggest you running the WRITE ZEROS command only after you've recovered your files. Here's a link to the software:
http://products.wdc.com/support/kb.ashx?id=0h5J2j
How to test the drive's health:
http://products.wdc.com/support/kb.ashx?id=8kKppF
How to low level format or write zeros to the drive:
http://products.wdc.com/support/kb.ashx?id=iUElG4
Hope this helps. Keep me posted!
SuperSoph_WD