The Windows PC has what is called Plug and Play (pray) or for short ?  PnP.
Each device in a PC has an  identification register that tells any OS what you have plugged in (in ROM like device)
Even RAM has SPD chip to tell the PC what DDR  memory is present and full spec.'s on it.
The Process in BIOS or the OS are called PCI scans  (even BIOS uses a keyboard and uses it after it scans)
Wiki:  PCI 

Once the Device  found is fully known, then a matching driver is obtained locally or the MS servers online for such purpose.(MicroSoft)
See how drivers work here.
" Drivers".                           
Some top drivers managers say there  are now 20 million drivers.(today 2019)
The top cause of bad drivers are upgrading the OS and there is no support for you PC or any of its chips, cards and devices. W10 Upgrades top this list
I call this slamming a PC,
Second cause is not having ethernet connected to your router installing new OS or upgrading or adding devices, (fail you mostly will)

First we need to learn who's drivers are best or not?
  1. The best drivers, are from your OEM (this means your PC maker, no better Driver exists) Some PC makers only support the next way #2. (Dell.com HP.com or Asus.com)
  2. MS drivers are also the best,  in fact your OEM gave the driver to MS, but MS tests it further. (WHQL certified drivers)
  3. If you have a custom device, say  a fancy new GPU card,  get the driver from your card maker. I buy Nvidia so I go there first. (if the above #2 fails or is limited in features)
  4. Do not go to the Torrent for drivers, they are infected.
  5. Do not get drivers from BUBBA-Gold-Drivers.com (a made up name if you get my drift)  they are either infected, useless and then they want money for bad drivers.  (money for trash)

Do not say you were not warned, if desperate, run Virustotal.com first on the driver pack. (at the least)


The below is for the desperate. but careful folks.
The below is how to get them the hard way. (if possible at all and some chips  are not made now nor have  Windows10 drivers at all , in fact missing on the planet earth 100%.)

Plug and Play (PnP) (simple)
 
If you force plug and play in Device manager found in control panel, Windows will try to find the drivers in the link below.
The OS then using that  simple ID , looks it up next in the MS device catalog storage servers seen here: Using the direct MS look up manually
If this fails you can then try to run the W7 last made driver, in to W10 by using compatiblity mode.
We simply install the driver using compatibility mode.  (the driver.exe) we right click it and pick properties then Compat tab, and then select what it is, pick the driver installer, for  W7 or W8, as your case may be, going to w10.
Last is to pick Administrator mode. then run  the driver installer this way by hand.


The below is just a show and tell presentation,  running all my favorite sniffer programs but if you fear programs (software ) the use only Device manager to do this. OK? And is next.

Do this first: USING ONLY MS, WINDOWS TOOLS !
Device manager (DM) is first, fast and the most safe way to gain PCI facts:
The best way to avoid the below is to use your CAT/5/6 Ethernet port to get your  driver automatically or manually. (one simple cable to your router)
Example CASE #1: (reading the Device secret codes next) and then searching for a driver from the Chip makers web site.
If you are working with sound/Audio chip in your PC this is mostly doomed, as sound chips and things on your motherboard are very complex and unique to your OEM ( get them from the OEM or fail)
A dead WIFI chip  and Device Manager (DM) showed it missing, (or marked there as unknown or marked RED or YELLOW ) or with explanation point parked !
The maker Realtek, mostly ended all private driver support (my guess do to high failure rates) The OEM modifies the driver is why and that is the reason for the shut down. (Realtek.tw)

Click the start button,  then click control panel, and  in the list (or search box) find Device manager, bingo ! DM runs.
In the DM you see this this below. after picking your dead or failing device, (USB port must be good first for USB devices can work next)

You right click the failing device,  (in my case here its wifi or can be Ethernet both are important if you need a working Sub-LAN or need access to the internet.
See the  details tab?,  at red arrow below)
Then play with the PROPERTY  buttons.
And last chose HARDWARE Ids (means identification codes) as seen below:
See VEN,  Ven means vendor,  or maker, can by INTEL or RealTek and many others (vast), like Broadcom   Write down the first line now.
We will next decode the line in blue and find  the makers name and model device and then find a driver for it.

DM in all it's glory, simple as can be but key to finding drivers

Next I use the database scan , you look it up that way.
Once I know these codes, I can search online everywhere for drivers to match it.
I first look them up here:
Using the direct MS look up manually

We can look up the chip here in the databased to see if it even exists today.

The next examples are all using free software found on many safe web sites, and all my links are tested by me and virustotal.com

How to scan and sniff out , PCI identifications from chips.
This is one of the best, but sometimes it misses chips. (chip means DEVICE'S or means complex major IC's integrated circuits.)
#1 is Hwinfo32.exe (portable)   
This is Z270prime system.

The below I clicked (network) It is the Ethernet chip, and get the VEN = code and the DEV= code if this chip is dead or weak.



There are other tools that are full of malware,  that I never link up.

  Sniffer 3 is retired now and the maker ended support. (the old one is at majorgeeks.com)


Just VIDEO GPU in this section:
Examples of How to find other important drivers: (ATI/AMD or Nvidia ) both can be hard to find legacy and here is the trick.

Here are some examples at Nvidia.
  •  Like old Nvidia, Nforce chips
  • Here is the Nvidia trick , in this page, set the first toggle box line to LEGACY and see all drivers for all OS there, on nFORCE (they hid it deep with this trick)
  Do know that W7 was the last OS supported for most of these, old Nforce chips. But might work !
 Try it, see for  your self, what works.
This page works for old Nvidia bridge  Glue logic so chipsets and GPUs. Windows 10 seems to fail on any Nforce chips up to series 7.
Case in point, if the Ethernet chip driver is missing, here it be.!
If you need old Intel drivers, go to intel.com home. and get them.
Most old video cards and chips are not supported now, or not for W10.
Need AMD/ATI GPU support go there.
I show here examples of on top makers above and the 2 links below show the top makers and the dead makers.
 

The top chip makers are here today.

See a   list of old defunct chip makers,

The fastest cure, after PnP failures is to let PnP find it on the internet, "BE CONNECTED"
The HP.com site has all my drivers,  I then load them all and now it works great. (in the correct order , I do that) Older that 10 years, last model made , HP support ends.
Lets say you are trying to buck the system and run a newer OS on your old PC, that HP.com does not support, well you get to do all this the the long hard way... (It was your choice, bucking the HP system of full support, Why do that ?, I DO but I know how to...)

PCI CODE decoding is easy try these: The goal here is to find maker of said chip then what chip it is, exactly "maker real name and chip model numbers"

Use these alternate database tables and look them UP now, , after you  scan , your PC and learn VEN/DEV codes seen below.  (A good place to see links to PC ID repositories is here)

The above data bases convert the codes to real makers names. and model numbers of chips.
The above 10EC chip  is a RTL8168E, Ethernet chip. (wired networks)
We could go to RealTek.com and get the driver from them, now that we know the makers true name and chip name. (my RTL8188EE chip now fails with the last w10 update MAY2019)

But first we look at Microsoft's solutions next.  Using the VEN and DEV codes as Microsoft search below makes for faster and more accurate look up of your driver.

Microsoft's  manual  driver search engine:   This is the PnP data base at MS.  New PCs use this and no user intervention is needed, and works automatically like magic.
But if not, you can go here and find  a driver any time you want.
 


One can go here and search many ways. (VEN + DEV) Or just VEN code or even makers name like Nvidia.
A chipset number, or sound chip #
Here is me searching now, at MS.




See a  
list of old defunct chip makers,  there are more dead chip makes than alive. (or the big fish eat the little fish and ended support on legacy chips)

Simple Cures, not possible above:
Best and last of cure topics is if one device is dead, and no driver exists,well remove it or disable it in BIOS and buy a new device,  a new USB WIFI dongle is $4.?
A new GPU card, a new Ethernet card  or a new USB 3 card. (Desktops rule the world of upgraded hardware, it is near endless my choices)
or load Linux and be happy? Ubuntu, V16 up.?







Links to free software to SCAN or SNIFF THE PCI BUS.

  1. Run HwInfo32.exe (portable version free) Best in class !
  2. There are endless examples of PCI scanners I do have most of them here., but the above is free of cost and  virus and malware free as many are not.



ver.8:::::::4-15-2017, revised 10-10-2018 ( 5/2019) even less.  and less again. v8