I have recently completed an In-Place Upgrade from Vista x64 to Win 7 x64 on my HP dv9820us laptop. Following an upgrade from Firefox 6.0.2 to Firefox 7.0, on attempting to access each of my Firefox and RoboForm2Go programs, I received the error "XULRunner-couldn't load the XRE function". I understand, from reviewing some posts on oter user forums, that there are some incompatabilities between Win 7 and some older programs, or their add-ons to firefox (and IE9?). I have already tried uninstalling Firefox 7.0 and re-installing it from a downloaded version from the Mozilla website, but the same error occurs when I attenpt to open Firefox 7. Somewhat strangely though, the installation process was able to directly access the Firefox website for the "thank-you" for the download. What is the nature of this error and how does one correct it?