I've clean started with no extensions, etc and same issues. All started after being forced to the esr channel and 52.5.0 installed, and gets worse with each update to 52.5.3. After a few minutes in Facebook groups (single tab), FF begins to crawl. Task manager shows much of memory held by FF. even with a single FF tab. and Launching FF is much slower. And forget about shutting down. i almost always have to kill FF (and associated plug-in container) via task manager. I've scanned for rootkits, worms, etc but everything checks well. And have Flash disabled (using default installed openh264 videocodec by Cisco AND PrimeTime Content Decryption module by adobe). But the FF issues show themselves even on sites without video/flash content. Again, never had thee issues before being forced to the esr channel and 52.5.x Yes, it's windows XP SP3. I need this laptop to last up to the summer, til I acquire a new one (waiting for laptop with the new Intel/AMD chip).