After the latest windows update, Firefox has been running unbelievably slow. I've tried refreshing, reinstalling, updating java, turning off windows defender, and just about everything else that's been mentioned on this site. Chrome/edge work perfectly, and the only suspicious performance issues involve my hard drive usage spiking to the 70% range whenever firefox is loading a page (albeit painfully slowly). Memory and CPU usage is similar across web browsers, but chrome/edge don't cause a spike in disk usage.

In addition to the slowdown, my bookmarks have all but vanished. Attempts to back them up result in a "unable to process this file" error message. I've tried uninstalling and deleting as many mozilla files as possible; program files, old data, etc.. prior to reinstalling, and still the same problem exists. Firefox still works wonderfully on my laptop, which hasn't been updated, but is seemingly permanently laggy on my desktop.