Can you install the windows 7 RC on multiple computers? I want to try it on different models and configurations to see how it works on older as well as newer computers. Can I do this?

Sure, just don't activate it yet. You have 30 days to activate. That's more than enough time to decide which one you want to keep.

According to the FAQ:http://www.microsoft.com/windows/windows-7/faq.aspxyou can use one key to activate Win7 on as many as 3 separate PCs.It wouldn't surprise me if it worked for many more than 3. (I don't know how many keys were issued for the beta, but I've read claims as few as 10.)