I found the site this morning. I don't know what went wrong yesterday. I did the download and installation successfully on my Mountain Lion disk, except that Windows balked when I tried to install it. The workaround was to do the Parallels 7 installation again on my Snow Leopard installation, which was working under Parallels 6. Since Windows was already running there, it didn't cause any problems. I don't know if this comment is appropriate to this thread, but I'll throw it in just in case it will help someone else. Before I upgraded to Lion from Snow Leopard, I copied my whole Mac disk to an external drive. That gave me a complete duplicate of everything I already had installed. When I upgraded from Mountain Lion to Mavericks, I didn't do that. I installed Mountain Lion on an eternal disk after the fact. That method obviously doesn't result in everything working the same way it did before.
Thanks for your help.