The major thing we worry about in Process Explorer is Interrupts. If it stays low then that's good.
Latency Mon was saying:
Your system appears to be having trouble handling real-time audio and other tasks. You are likely to experience buffer underruns appearing as drop outs, clicks or pops. One or more DPC routines that belong to a driver running in your system appear to be executing for too long.
If the problem is gone it will say:
Your system appears to be suitable for handling real-time audio and other tasks without dropouts.
LatencyMon has been analyzing your system for 0:00:06 (h:mm:ss) on all processors.
Not a good idea to disable the Java Update Scheduler if you have Java. Actually best to uninstall Java unless you have some real reason for it.
For Firefox try running it in its safe mode:
If it runs quickly then the problem is an extension. Try disabling about 1/2 of them (restart Firefox) and see if that makes a difference. If it does then 1 of the extensions you disabled is at fault. If not try the other half. Then enable 1/2 of the 1/2 you disabled. Try to isolate the problem to a single extension.
Most obvious suspect extension would be
FF Extension: (Honey) - C:\Users\Bob\AppData\Roaming\Mozilla\Firefox\Profiles\iewfce5i.default-1526099188072\Extensions\[email protected] [2018-05-14]
Speedyfox can also help with slow Firefox:
http://www.crystalidea.com/speedyfox. Close Chrome/Firefox/Skpe. Hit Optimize. You can run it any time that Chrome/Firefox seems slow starting..