Well, there's yer problem.
Suggestions: Will the fire breathing beast write CDs or DVDs? If so, carve you off the least-referred-to info and burn backups. Neatly labelled, logically grouped, and in multiple copies. Aim at 10-30% free space on the disk, at least. THIS IS NOT GETTING RID OF INFO. Slap down the anxiety and tell yourself firmly that you can get to the stuff any time you want. Faster than sometimes, since a reboot will be less often a part of your normal process. A stack of fifty CDs or DVDs can be had for way cheap, if one waits for a good sale.
Jack that puppy up on some kind of stand. Anything, so long as the air ports are not lying right on cloth, table, or you. I have an old laptop mostly unused because of just such overheating. But even something like my reasonably clean work laptop, if my wife tried to run Facebook games like Farmville (a surprising graphics hog) or if my kids tried to run even a modest game, the cpu or gpu (no idea if it has a separate graphics processing unit) would get blazingly hot. Hot to the point one can't leave it on one's lap w/o pain. A cheap lap desk with a bunch of holes cunningly hacked into it would get a couple of inches of free airflow, and should way cut down on the heat buildup.
Now go to the sysinternals website (google Microsoft sysinternals). It's a site run by Microsoft to offer some utilities for free that I wish they would just put in the operating systems. Install one called process explorer, answering some question or other "yes, i would like to replace my task manager". Task manager is the rudimentary view of what's boinging around in your 'puter's tinny mind at any one time - the one you can bring up with a SINGLE! control-alt-delete. Once installed, (SINGLE!) control-alt-del, choose task manager, and see the process explorer. View -> system information will give you a graphical representation of how clogged various capabilities are. If yoiu keep those visible - mine show up as tiny graphs in the system tray, bottom right, when minimized - you can get a good idea if this slowdown I'm experiencing RIGHT NOW is due to no free memory or some such. If RAM in use is peged or nearly so, one might as well start closing things, 'cause the flaming beast is about to close them for you anyway. I have locked up my drawing program, closed, oh, saaaaay the Firefox with seventy tabs open, or the Outlook that's referring to several gigabyte size mail files, and voila - I temporarily have some free memory and PhotoPlus will be responding - maybe long enough to save my work!
Now, about those scads of tabs. Watching process explorer when you have few or many open will start to give you an idea how much of a hog a many-tabbed browser can be. FF has the benefit of an extension (or is it now built in?) where for the last FF window you close it'll ask you "want to save these tabs and restore on startup?" Watch for other FF windows open - error popups, ad popups, and a download pane all count when trying to get things down to the last window with stuff you care about - only the last closing seems to offer this saving option. Again closing thattaway does NOT lose you any info so slap your inner voice of panic upside the head with a large fish, tell it to shaddup, and properly close the browser. That is, if things are getting too hot or too slow or too laggy, or whatnot. If things are hunky dory, sure, leave all seventy open so you don't lose your place in researching the third rabbit trail that came up amid the second rabbit trail that arose while pursuig the first rabit trail which.... dang. Forgot what I originally was looking for again. Probably sixteen steps back in history on tab eleven, there.
Notepad and calculator are pretty cheap, size-wise, so they don't hurt much. The MMORGs? Uhhhhh .... those are gonna play hob with your drawing package. And eat graphics power. Pick game or draw, at any one time. *Consider* offloading your music to another bit of technology while drawing. some interfaces are lightweight, others eat your CPU and bandwidth so just watch the various process explorer charts and see what seems to use up the most memory.
You CAN kill processes right from that process explorer window - just don't. Unless you have no choice, like mail is stuck, and won't respond even enough to close genteelly.
What mail client do you use? Some are hogs .... >cough< Outlook >cough<.
"Six instances of Word open for writing".... I'm gonna go out on a limb here and suggest you separate writing and formatting. Word can be final draft, and a fine job it will do. Until you get through collecting most of your raw words don't tweak the look so much - you KNOW you do :-) -- rather capture raw blocks of verbage in say Notepad. D/L a notepad replacemebt like Notepad+ or Notepad2, by the way. A teensy bit more functionality, without being even as bloated as wordpad, let alone MS Word.
If you knew me you might think I would suggest dumping MS Word and using Star Office or Libre Office (free , open source, file type compatible!) instead. No - I've found both those to actually be slower than MS Word. My experience, my circumstances, YMMV.
The sizzling and smoke thing is why your system acts underpowered. Electronic devices run on smoke. When you let the smoke out of the chips inside, said chips and hence said devices will quit. And I've NEVER been able to get the smoke back in.
Seriously, if you had ANY resources to replace stuff with, those symptoms say "please replace me before i crash and burn, taking your house with me". Since you don't, then the run-better steps above are a teensy bit of betterment. Or a large smidgen. Or sometimes a whole heapin' helpin' of ....
Speaking of incineration, while you're making multiple copies of less-used info that you're going to keep close at hand,, why dontcha likewise make backup CDs or DVDs of ALL your critical stuff? Because one day that snap crackle pop ain't gonna be rice krispies cereal, it will rather be all your lovely files singing a goodbye song as they sprint out into the vast bitbucket in the sky. Forever.
Anyhoo- you've got options. Plentyof them, and cheap or free.
