Yippee!!!!!!!!!!!!! It worked!!!!!!!!!!!!!!!
Okay, here's what I did. Hopefully it will help others out on this forum who might have been as frustrated as I was. I guess previously I had downloaded a different zip file and tried to extract that. It made a folder called Rainbow2006Release when unzipped. That doesn't work. If this is the folder that was created when you extracted the file, download the .rar file and extract that.
The .rar file needs a different extractor to unzip - it doesn't use WinZip. Another hurdle, besides having the new project type installed for VS2005. I downloaded a free trial of WinRAR. Once you have a program that will extract .rar files, use it to extract the Rainbow.Portal.2.0.rar file. I opened the .rar file in WinRAR and selected the Rainbow.2.0 folder (there are two folders, one with a ".." as the folder name and this one). Select that folder and extract it to the wwwroot folder on your system and it will create a folder called Rainbow.2.0.
Now, here's another step. *Make sure this Rainbow.2.0 folder is configured as an IIS virtual directory!* Also, make sure it's set up as a 2.0 application.
After all that, I was able to double click the Rainbow.duemetri.suo file and it opened in VS2005 without a problem. Hope this helps! Now, on to figure out Rainbow!!!