If you just installed Windows and only now are reading this guide: Windows is probably already installing drivers for you and hopelessly failing at doing so. Disconnect the computer from the internet and disable the automatic installation of drivers.
On your keyboard press; Windows key + X System Advanced System Settings Hardware Device Installation Settings
Windows will start downloading and installing drivers immediately upon entering the OS setup process. It's best to not have the machine connected to the internet at all when doing a clean install to prevent it from installing any drivers automatically before you are able to disable this feature.
If Windows has already installed some drivers you might run in to issues when attempting to install those drivers manually later. Don't be alarmed when a driver doesn't install because you are already "Running the latest version", you can ignore this and continue installing the other drivers.
First you need to know your system's specifications. You can find your system specifications quite easily in various ways. The specifications we are interested in are the make and model of the motherboard, the GPU manufacturer (AMD, Nvidia or Intel) and model, and the make and model of other "special" devices such as liquid coolers with a USB connection, Wifi cards/dongles, RGB/LED controllers etc..
You can use software such as Speccy and CPU-z to list your system specifications. Speccy will list your system's specifications inside it's easy to understand interface. CPU-z can be used to 'validate' your hardware which will push a list containing detailed information on your system specifications and configuration to the CpuID website, this can be very useful when sharing system specs with other people since you can simply share the URL.
You can find information on the motherboard and GPU in msinfo32 (System Information). You can do a online search on the listed PNP Device ID under the "display" catagory if the GPU model is not detected.
On your keyboard press; Windows key + R type: "msinfo32" and hit enter
Using the Device Manager you can find the device IDs of networking devices, audio devices and graphics cards. Simply do a online search with the device IDs. Do be aware there are tons of malware spreading sites which popup when looking for device IDs, don't download anything from these sites.
Right click the Windows Start button Device Manager Right click the Device Properties Details From the dropdown menu select "Hardware Ids"
The Device IDs themselfs also give away some information on the device manufacturer, VEN_8086 being Intel, VEN_1002 AMD, VEN_10DE is Nvidia etc.. the board manufacturer might alter the Vendor ID, so your Nvidia GPU could have an Asus Vendor ID.
Another way of identifying hardware is by looking for stickers, labels or model numbers on the hardware itself.
Graphics cards for example often have the GPU make and model printed on them as decoration, the make and model might be something like Nvidia Geforce GTX 780 ti. Nvidia being the chip designer, Geforce being the product type and GTX 780 ti the model. A GPU might also have labels containing the make and model or a hardware ID which you can identify with an online search. The same applies to motherboards and other devices.
Download your drivers from the manufacturer's website and not somewhere else. There are hundreds of sites on the web which spread malware disguised as "drivers" and "driver updaters".
The manufacturer might list driver updaters, system optimizers, anti virus scanners or other pieces of software on the driver page. It is recommended that you do not install these since all these programs do is hog system resources and data mine for no gain to the end user. Also properly read before clicking "next" while installing drivers, some installers like the nvidia one might install unwanted bloatware which has to be disabled manually.
Here is a short list of a few sources for drivers.