I went into %TEMP% to clean out a bunch of temp. files and while there, decided to get rid of a bunch of ISO.s from Linux distros I had downloaded to a USB (trying to learn the Linux language-losing battle). So, when I click delete a pop-up tells me that the file is still open in the system. I have checked in disk management and the task manager- no success. Is there anywhere else I should be searching? I am running windows 8.1 on this unit, thanks.