rar is a type of zip file you need to open it go to cnet.com and search for a freeware I use frog I know others use different ones.

http://lp.jzip.com/?sysid=102&appid=100&gclid=CIma5fDSi7MCFRGqnQodsGAA2w

I use 7zip to unzip the rar files.

I use embird to open rar files. You are definitely not out of luck, just need to do an extra step.

I open all my files (RAR & Zip) using 7zip, then I use either truesizer or my editor to open the file (at this point use All files so it will open all the different embroidery formats)
hope this helps :)

As others have said, a rar file is a compressed file, like a zip, and holds information. I found 7zip through Cute, and it is very easy to use. Once installed, you right click on the rar file, and a menu pops up, slide down to 7zip and click on it. Choose extract here and a folder with the designs appears. You can then delete the rar file, and open the folder. The files are whatever the digitizer made them to be. Most of the time I find pes there.
It will work on zip files, I found I can open a bunch of them at the same time, just highlight them all, and after the files appear, you can delete the zips.
Jo