I have (backup laptop) a HP laptop with a Intel Celeron 877 and 4 GB of memory and Win10. Its OK most of the time but every once and awhile while using Thunderbird for email, I need to pause for a second or two typing so the letters displayed catch up with what I have typed. Annoying. I have brought up the Windows performance screens and never see a high CPU usage nor high storage usage nor high page faults. The storage usage is typically 70% to 80%. Given the low Passmark rating of the Celeron 877 I am convinced that the laptop is doing all it can and not much I can do except to get a faster laptop. Most of the time I only have Thunderbird email and several tabs under Chrome running.