I have downloaded a three-part file, all ending in .rar , however when I try to open these files with WinRAR the following error message pops up: "The archive is either in unknown format or is damaged."

I also tried to use ISOBuster, a program which creates image files, as I thought the .rar files may have perhaps been three parts of the one image file, but no luck. The program could turn them into three individual images and burn them, but when I looked at the cd in the end it was blank.

So, is there a particular way I am meant to install/access these files, or was I duped?