Firstly, try the next link to virus chest - Scan history - It should have it listed in there.
But to be honest I am thinking that it may be a hardware issue. Lets take a look...
Seatools Scan
Close all open windows and browsers.
- Download Seatools from here and save the file to the desktop.
- Right click SeaToolsforWindowsSetup and select run as administrator.
- Agree to the licence agreement and follow the prompts to install.
- Once completed, start SeaTools for Windows and accept the licence agreement.
- Select your drive by placing a check mark next to it.
- Click Basic Tests and then Long Drive Test
- You will see a progress indicator to the right of the drive selected. Once finished, post the results here.