Can't delete files

I am trying to reformat and clean up the entire drive, but there are two .png files that cannot be deleted and therefore, all operations stop, even re-formatting.

How can I delete these little **bleep**?


Which Operating System are you using?

What, if any, messages are being displayed when you try to delete the files?

Thanks for response.  XP Pro.  No error message, just nothing happened…


I tried again, but using quick format and it worked, but then had to use Smartware to erase so that it could be used.


I use  MacBook Air OS X 10.7.5.

I am not able to delete anything from my WD external drive. That option is not showing among the usual possibilities of actions.