Unable to access my files and folder names are symbols

Strange. My WD1600XMSB-00 stopped working properly after sitting on my shelf for about a month. Not just inaccessible files, but also strange unrecognizable symbol file names. The file names now contain Greek letters; looks like German letters too; geometric shapes like boxes. Very strange. Anybody know how to fix this?

I just noticed that some of the date modified took place in the future.

1st thing I would do, is run Windows chkdsk (Check Disk) and also try WD Data LifeGuard Diagnostics to check the health of the drive