I just looked at that site. They are sending PDF forms without an extension added to the filenames.

I just looked at that site. They are sending PDF forms without an extension added to the filenames. That could be why you are having a problem. I was able to download them, add the extension .pdf to them, and open them with a PDF reader. Does Windows 7 refuse to download files with no extensions? I have no way of telling that, because I use Macs.