My PC overheated ! 
I wonder why?
Most PC's have a  fan, at least one, to keep it cool.  
All electronics parts (chips for sure and CAP's) do not like excess heat, too much heat and all fail, some chips get super hot and fail fast,  the top 3 are , CPU, GPU and GLUE chips.
The 2 bit processors, the CPU and GPU both can add up to 200 watts heat, full tilt. (high end  Desktop PCs)  (here RUN FAST)
If the heat is not expelled to the room (space)  that the PC resides, then that chip overheats and can do so fast, some in seconds flat !
The CPU has over temp sensors that cause the processor to shut down all by itself. (see here how this Intel magic happens)

Covering Desktops (DT) and Laptop/Notebook/pads (LT)  (this is what we call a NO BRAIN'R)
The Cure is simple.
Laptops waste  up to 50-100watts power in heavy use, is the range running fast App's, this heat is all mostly inside and must escape, if not allowed to breath and escape, and vent  the hot air, parts inside over heat and fail or self shut down.
Gaming desktops PCs can use 2 times that power level and attendant more heat.
( Blowing up a $300 CPU/GPU  is not good  ?) 
Heat is the number one killer of all electronics.!  (besides lightning and floods or you  dropped it 6 feet to concrete floor)
The ugly photo's below are all neglect. 
(even 1 year of neglect can pack a fan and faster with pets)

I will do a slide show now, to show how classic filth kills any  PC DEAD!

The cause and cures,  can be presented near wordlessly.  Look , find dirt and clean. (end story)  99% of PC are now cured. (but not all)
What needs be said,?
This first photo speaks 1000 words.  or just 1,  neglect. (the 1000s words would be fixing some laptops, as some are a PITA like Toshiba's are)

  • I will state the obvious, in simple lines of short text.
  • The vents must not be packed up in lint (I will just call that packed for short)
  • The Fans , 1 or more,  but all must spin and blow air and not be packed.
  • The heat sinks, seen in the slide show must not be loose , or falling off or packed up in dirt and or lint.
  • The PC must breath fresh clean cool air or the PC will fail. (check all vents ,not just exit vents but induction vents (those that suck air are induction vents)
Now examples:  (5years of neglect?)
we say RAT NASTY , at first glance.!

More examples.
Desktops are so easy to clean , just 2 screws left cover off, and gentle vacuum it out first then go outdoors next, and the use CAN-O-AIR.
I can go to the garage, fire up the (SHOP AIR) compressor set the regulator to 20 PSI, and blow out a Desktop in 5min work.  I do so once a year. (less now with my new hardwood floors)

More Neglect:

Laptops are not easy (unless lucky)  to clean or service. but lets  do some now...
The laptop can be cured in many cases(no pun) not dis-assembling the complex case , by simply blowing out ALL vents clear of lint, and for sure the 1 exit vent , be sure to back blast it., with CAN-O-AIR.
In more extreme cases of overheating one must take the Laptop apart, or first remove the keyboard and blow out things from that huge gaping hole you just made. (get serious with the fan port seen below)

Example Toshiba , not too old. 2008? then a 2009 HP later...
See this heat radiator, left end? "A" ARROW  below it must not be allowed to packup in lint.   (Back blast the port B now)
If the fan is dead, clean it first. This will cure most fans from stalls. (for sure hair balls from pets , ouch)
See the FAN,at "B" ?  that fan must NOT be allowed to be packed in lint , in fact if you ignore the packup this will stall the fan and the CPU will shut it all down ! overheated,  "intel inside" did that, like magic"

Removing just my keyboard or case top, helps greatly here to clean the fan and Radiator (RAD) seen here, (a Toshiba and is horrible to undo hidden plastic snaps, I hate Toshiba LT  , these was frebee, I'd never own one...ever.)
 I'm upgrading this one to LED screen for a friend. (the CCFL lamps died)
Laptops love to overheat way before any desktop. (due to that RADIATOR port being so small , see marked A above.)
The same goes for all bottom vents below, if you run the PC on a blanket it will overheat, or if the vents on the bottom are all packed full of lint, it will overheat. 
See those 6 vents on my Great Quality HP laptop? below?, do not block them or allow them to pack in lint.
SOME LT, the keyboard has vents around its rim, that suck air.  (if blocked?, oops a daisy)
ALL computers make heat,  (just like your cars engine does) and you must allow it to keep itself cool (called thermal managment to an engineer) if not?, they all overeheat.

The Below is my HP 8540W. See the vents,  keep them clean?
If need be...
Rule one, is to go to or (the 2 best makers ) and download the offical SERVICE MANUAL or your exact PC,laptop, then read how to DISMANTLE it. (if confused ?find a real tech in a real show  and get them to do it) ok?

The HP 8540p/w series below the key board comes off with 4 screws , the screws on mine have cute white icons labels , for keyboard.
Every year, I  back blast the fan seen here to keep the radiator clear and clean.  (I blast it both ways at all  vents and on left then at fan port)  30PSI max if using shop air like me.
Back blasting works best with keyboard removed.  (let the dust cloud float down the drive way to the street)

Facts: The heat sink tops, Not the RAD or copper pipes run at 100F (38C)   (if say the hidden radiator on the left , is packed in lint then the heat sinks get way hotter and faster, and then the CPU shuts itself down.
Most if not ALL PCs have 2  shut  down BRAINS, All CPU's will self shut down, and in almost all cases the BIOS BRIAN can too.  (goes slower then if unmanageable still, boom shuts down by DESIGN)
The GPU runs at 105f (41C)   if the fan fails or packs in lint or the RAD it will overheat real fast. (8540p) (IR thermal GUN READINGS BY ME)
The CPU shuts down at  about 90C, never let any CPU run anywhere near that.
A goal for any CPU is about  50C max, some go to 55C, well away from 90c trip point , see?  If the fan works below and the RAD is not packed in lint, it will run cool or the TIM is bad.
One odd  thing is if you remove all RAM the BIOS goes dead, and the fan too goes dead, so do not run it RAM free, for  more than SECONDS. My LT has 4 RAM stricks. 2 top , 2 bottom.
Test RAM 1 stick at time. (testing for bad RAM)
THE RAD can only be seen looking in the left side vent, it can be back blasted with air to clean it out, but the keyboard is best removed for the filth to land somewhere good like the back lawn or driveway, not inside case or home.

If you don't keep it clean like above, (annual)  you then  get to do this  horror.  taking the full top off, then remove 9 heat sink screws , clean it all on a bench the use this TIM  to put back all heatsinks or heat pipes
In most cases I never need to strip it down this much,  I use the air blower to blast it out 100% free of all lint outdoors.  Keyboard out , really helps greatly,  do not force those tiny connectors, learn now to deal  with them gently.
Some heat sinks , I discovered the HS compound turned to hard fractured glue, the cure is this.
WARNINGS: (to non-tech's)

The laptop has tiny frail ribbon connectors there are 3 types, force on,  hinge type or wedge type.  (each type is a skill set all TECHS learn fast, or go broke)
If you break one connector (not cable) , it's a $100 to $300 fix. (you get to buy a new Motherboard now)
If just  one cable is bad , you can buy them best place is Fleabay used.  Most PCs new parts sales end like in 3 years,(yes, sucks)
If you fear damage, why not ask your PC shop to clean it for you.  They know all about this  , I promise.

The cure for LINT: 
Can o Air. duster

Take it outdoors, and blow it clean  using shop air or CAN-O-AIR (duster) sold in all good stores.  (never exceed 30 PSI pressure)
(I do use a vacuum cleaner first,  on the worst cases, see far above , then SHOP AIR with the 30 PSI regulator inline...) NEVER BLAST using 150+PSI shop air, ever.
Then blow all heat sinks and fans clean.  (and annual event here) always do this outdoors, never inside... It will be a nasty cloud like PigPen(tm) cartoon character. (wear PPE,  gear while doing this, or risk eye damage) wear GOGGLES !

Intel proof of Processor CHIP DIE LEVEL protection: "Thermal Shut Down"
CPU: (the first time you will discover this is the first time the heat sink falls off.)
The Intel chips have this feature for many many generations, it's not a new features  at all.  (THE AMD processor does the same thing for the same reasons)
In FACT Intel CPU (and AMD) auto self shut down and HALT when too hot. (in seconds) Read page 36
From"Intel 64 and IA-32 Architectures Software Developers Manual Volume 3 (3A & 3B): System Programming Guide" at

Section 14.5.1 Catastrophic Shutdown Detector
P4 family processors introduced a thermal sensor that acts as a catastrophic shutdown detector.

This catastrophic shutdown detector was also implemented in   Pentium 4 ™, Intel Xeon™ and Pentium M™  processors. (relics of the past now but all processors have  today)

It is always enabled !

When processor core temperature reaches a factory preset level, (90-100c?) the sensor trips and processor execution is halted until after the next reset cycle.

This  mechanism is built-in to the processor. (self contained, there)

But do know Most BIOS BRAINS (code) have there own thermal controls and its own sensors and will speed up the fans or shut down the PC.  (independent of Intel magic above)

I even run fan controls in windows 10, a 3rd level of protection !

There are pages like this, for every Intel CPU made, this one goes in to great depth, no more guessing.

Covered here too, on modern Intel,  CORE2™. (see all pages  on thermal protections)
Question of the day 1:
Why would Intel let you burn up any $300 t0 $500 processor? answer: they do all that is possible to protect  itself from permanent damage.
Nor will let there CPU burn up. (By Design)

HOW CAN THIS HAPPEN?  (TIM = thermal interface material) or Heat Sink Grease (or compounds) We call this thermal compounds.
There are many makers of the compound, and clones and junk sold on fleabay , if you have  cheap PC with slow processor it will not need TOP PERFORMING Grease.
If the processor or GPU is faster, it will love the below show grease, that I have personally tested. (and tried all other top brands starting at Dow 340) This is not SPAM here, it's personal advice based on facts.
  • A Filthy PC, as stated above.
  • The CPU heat sink (HS) fell off the CPU, touch it gently feel it, is it loose, oops. (fix this now) Mostly this happens on desktops, even shipping damaged.
  • The CPU fan is dead or the HS fins are packed in lint making CPU cooling  near useless.
  • The Radiator is packed, see above.
  • The TIM failed, many PC makers use some cheap crappy thermal compound that gets hard,cranks and now can not do ITS JOB.
  • The best TIM is one that never gets hard
  • Some fly by night sellers (vast) try their best to fool you with magic (SILVER,GOLD or even NANO CARBON ) those are liars. Every one. The good TIM , read the ingredients. see no silver.
  •  a.k.a , China Snake oil/grease.(endless sellers of lies and BS) Learn that there are real products made by real companies with real names, not SOM TING WONG made. dig?
  • The CPU HS (heat sink) clamps are bad/Failed or were messed with by the BAD GUYS.
  • The PC PSU and case fans all failed, making the inside of the case roasting hot and the CPU fan can't find cool air to do its job and fails.
  • The GPU chip can overheat too and the LCD screen now goes dead or wonkey (for the sames reasons state above, the Heat sink is not working at all)
I tested this TIM product my self , and have at least 5 other top brands of TIM   and this one works on my very HOT running old Intel i7 processors.  See the spec.  from SHIN !
For my cool running i5's any TIM works great, even my old tube of 1970, Dow Corning 340, I've used that for 45year now no problems until you run in roasting hot CPU or  a fast GPU. (Some GPU can burn 150w of heat , gaming systems)
Some Intel i7  processors run  very HOT in  GENERATION #1 2010. (this is largly gone now on newer generations of laptops) Getting lower each year, , but later Gens can be as low as  17watts.
My fastest Desktop CPU runs 100watts +  (it's really  a powerful workstation.) (hint, look up your CPU at say intel and read the watts, and then use a COMPOUND that matches what you need or just get this.

Shin X23 is good.(really all are, by them.)

Shins best, is there, X23-7921-5 ( note this parameter "Thermal Conductivity(W/m K), >6.0") a hard number to beat !!!

See Shins chart here for the best performing TIM.

I do not get paid to say any of that, all comments are based  on my careful tests, on real PCs that overheated with other top brands and only this worked perfectly. 
The only way to test the TIM, is to test  it on a real PC that runs very hot processors.  (ambient temps 70F , controlled spaces)
It is true that some slow or very low power Processors even pass the tooth paste test (for TIM),  (but won't last for 10 years, would that ? , no!)

Jargon: 101
CPU, the central processor unit chip, see here.
GPU, graphics processor chip,see above link.
MOBO the mother board seen here,  or seen here.
TIM , heat sink grease.
Heat sink, that metal heavy object seen on top of chips ,that tells you that chip RUNS HOT and needs lots of fresh cool air, make it so and win.
RAD is Radiator this is only seen on laptops,with a fan and thermal heat pipes,  These pipe flow heat to the RAD and then the fan blows it out of the confines of the Case to the world. (heats your room it does) even as much as 100watts heat.
PSU, power supply unit.

The HP service manual for your PC covers , dismantlement.  RTM , read the manual and not guess. hit home above, then click HP help links.
Glue logic are the other large chips not CPU, not GPU , one is called the North bridge and the other South bridges, they too must not overheat, my x38 chip runs hot and it too has  heat sink. (that must have cool air available)
If seen Glue Logic chips that have have  just a heatsink on them and seen them fall off too. ( some are clamped on others glued on (thermal glue) the former can fail easy.

version 10.  7-25-2017  (covering topic, "taking out the TRASH"), by: DeadPool  ,revised  5-1-2018