Alot of people rename there big .iso and .bin files to .exe so they get catogorized as "software" to aid searching and not "image" (iso) or "other" (bin) and they wont actually run. you need to either change the ext to .iso to do this open any folder then on tool bar click tools>folder options>view and then untick the box where it says hide extensions for known file types and apply, now right click on the file that wont run and rename it changing the last 3 digits to iso or bin, you can then open these files with isobuster or winiso and extract the files to a folder and run it from there or burn to disc. or install deamon tools and mount these types of file in a virtual cdrom drive (This doesnt apply to the large zip or rar self executing .exe files, just the large .exe files that have the blue and white box software icon )

also all what has been said about using a good av is very good advice.

hope this helps ya