What the Hex Is this "System Idle Process," & Why Does It Use So Much CPU?

I'll look at that to see what's up, but I think I meant to ask something more-like 'How do I get my computer to spend that CPU doing what I'm trying to get it to do now?'

It seems that, really, you are dissatisfied with the speed of your computer and, in particular, the fact that Firefox won't close like a good, obedient application. If I were in front of your PC, I would start by looking at what version of Windows you have, what version of Firefox you are running, what version of Java you have, how much RAM you have and whether there are unexpected processes running (in spite of what the System Idle Process says ... it can be stupid). I would, perhaps, use some tools to delete unnecessary files from your hard disk and cookies and history (depending on whether or not you minded) and to defragment the hard disk (even though it may not be strictly necessary). I would also make sure that your anti-virus program was up to date and run a full scan. That would take some time, so it would be time for some refreshment. Having (hopefully) found nothing untoward, I would make sure that Windows was up to date and that Java was the latest version. I would then download and update Firefox, paying attention to any add-ons you might be using. If there still appeared to be problems, I would begin by disabling all the add-ons to see if that made Firefox run as it should. If so, then I would re-enable and test them one by one, leaving any non-native search bars and toolbars till last. After this, I would be surprised if your system were not running a great deal faster. If it was still not up to your expectations, I would suggest that you either buy more RAM (if you did not already have the maximum) or (possibly) go through the whole process of reformatting your hard drive and reinstalling Windows and everything else afresh. That, however, is another day's work.

Thanks. I have- and regularly (about every three-to-six hours) run-cCleaner (a program that deletes a bunch of cookies, Recycle Bin files, Temp files & the like). If on pre-analysis of the files to erase I don't have at-least ten Mgs of files to get rid of, then I run my defragmenter's analyzer and then defrag 'if it tells me I should.' Maybe I'll 'Search the Web' to see if FireFox/'the experts' can tell me why FireFox does that cuckoo stuff it do ... are there any FREE programs out there that'll take care of all this for me (kinda like cCleaner except more 'rearranging' and not 'erasing')?