I cannot install Flash into Firefox, To see Flash content, I must use Google Chrome...no problem there. Way back when, I had no problems with Firefox. Though I am an administrator, I get the "insufficient permissions" message just before the installation is complete. I tried everything suggested in Adobe's help area in that regard. What I have tried: A new administrator account. Making sure I was running the .exe program and Firefox as an administrator. Delete and reinstall Firefox. Use the uninstall from Adobe for Flash, and then try the reinstall. Disabling all security while doing all of this. Installing in Safe Mode. I spend a few hours on this every month or so. A new install in Chrome happens. I even downloaded Commodo Dragon, and have the same trouble there...I feel like Chrome is wandering around inside there to keep me from using Firefox!!! I have been using Firefox for years, and still strongly prefer it, but I am about to give up.