you had previously unisntalled Firefox prior to this new install.
If so, I wonder if the prior uninstall did not delete everything. Unfortunately using Add/Remove to uninstall Firefox leaves a few folders behind, most notably Profile folders under your Documents & Settings account name folders.
I would uninstall again, using Add/Remove, then do a search of your computer looking for anything to do with Firefox, and delete them all. Then do the same for Mozilla. Then I would reboot, and use a registry cleaner like CCleaner to clean out any orphan Firefox entries.
Then reboot again, and try and install Firefox again on a clean system. Cumbersome I know, but I have had to do this myself when my own Firefox application started to go south.
I installed the Firefox Browser again to try it out. The browser loads up fine but when I click on to import my bookmarks nothing happens. When I bring up the task manager the CPU useage is maxed at 100% but the only thing really using CPU is the firefox.exe program which keeps jumping from 50 to the 90's.
When I look at applications its says that Firefox is not responding. I'm using the Keiro firewall and I made sure that its set-up for the Firefox browser but it still won't work. When I previously used tried the Firefox browser I was using the Zone Alarm firefall and didn't have any trouble loading the browser or importing my items from Internet Explorer. Any suggestions????