With paragon software you get a key that's kept on file in your paragon account. If you can find the correct version on one of the file download sites you should still be able to get the program working.
check your Email that was sent with the key. You'll notice lower down their's a link you your account page with your password and name. input those in the appropriate fields (once you're at the proper page) and it'll list all of the paragon registration codes you have. Some of them may akso have download links for the software, but not many of them.
All that said, you may have problems finding the correct version because I've just remembered they are special editions (basicallt versions that have had some of the tools disabled). I'd consider contacting Paragon and asking if it would be possible to get a copy of the file; explaining the problems you had installing it on the day. They may (or may not) give you a copy of the file or even a full version key for the standard version of the software. That isn't guaranteed or likely, but it's worth trying for this particular software, especially if you really wanted a copy.