InfoPath Dev

There is an InfoPath app on SharePoint built in InfoPath 2007.

 I have InfoPath 2010 and need to update the form, however, I don't have the form template. So I open a form from the SharePoint Library and save it to my computer, but I can't design it with InfoPath 2010. In 2007 you used to be able to right click a form and select "design".

 There seem to be a number of compatibility issues with it as well.

I think you may be saving an XML file and not an XSN, which is why you aren't seeing design in the right click menu. Is this form published to a SharePoint Library? If so, under the library's advanced settings you should see the path to the template and a link that says "Edit template" which would allow you to open the template in design mode.