I installed Nightly on windows 8 to play with the new Metro interface that is under development. I uninstalled it a while later, but HTTP and HTTPS links go to Nightly, not firefox, and I can't seem to change this in regedit or the control panel. FirefoxURL now points to the nonexistant Nightly installation. How can I fix this? Thanks.
I had the same issue. I gave all defaults to Firefox that it would let me. Then I used regedit and manually changed the data in FireFoxURL in HKEY Classes Root from Nightly to Mozilla Firefox. I then deleted all references to nightly that I found in the registry.
Hope this works for you.