Windows 10 (unfortuately) Home 1803 (OS Build 17134.472) Processor: AMD A12-9700P RADEON R7 10 COMPUTE CORES 4C+6G 2500 Mhz, 4 Core(s) 4 Logical Processor(s) Firefox (currently): Quantum 63.0.3 (64-bit) Laptop: Dell Inspiron 5565 x64-based PC NOTE: I read the thread here -- https://support.mozilla.org/en-US/questions/1239390 as in the beginning it appeared the OP had the same problem I have, but it turned out not to be so. Close, but no dice. I have Firefox set to just let me know when a newer version is available. Several days ago, FF started advising of a newer version. I put it off until about 27 or 28 December. I did not immediately restart the browser as I was in the middle of something, but it was restarted within a few hours. After clicking the restart button in the "About Mozilla Firefox" window, I got a UAC window, asking if I wanted to allow FF to make changes to the computer. I was wary at first since I've never had this happen before just updating FF. I clicked the "Cancel" button. When I launched FF again a little later, that same UAC window appeared, once again asking if I wanted to allow FF to make changes to the PC, and again I clicked the "Cancel" button. I then discovered that FF 63.0.3 had not been updated, and in the "About Mozilla Firefox" window, the button was still advising that FF needed to be restarted. The next time I launched FF and the UAC window appeared, I clicked the "Yes" button. However, this had no affect, as FF was still showing vs 63.0.3 and the button in the "About Mozilla Firefox" still indicated that FF had to be restarted. I realize I can just download the latest version, but I do not want to lose all my settings - it seems that nowadays, replicating the same/preferred environment is not as easy as it once was. I was going to try to restore to [a previous version] but that option was not available. I then decided to try a system restore, but according to that process, FF would not have been affected - no doubt because the program was never really fully updated. I don't normally allow updates so soon after a new version becomes available, and had I known this would happen, I wouldn't have this time. Is there any way to force the FF vs 63.0.3 to update to vs 64.0, OR... stop the attempted and subsequent failure to update? The PC has been shut down and powered up several times since attempting to update FF.