Since Windows 7 is now EOS and there have been numerous threads on this I think it prudent to have the most commonly sought Windows 10 upgrade information all in one thread. Please feel free to add your own tips and info here.
Windows 10 is a direct upgrade from Windows 7 (except Enterprise) Windows 8 and 8.1. The tool used to perform this upgrade is the Windows 10 Media Creation Tool
and at this point, still provides a free upgrade path for all supported OS's.
If you wish to do a fresh install, the same tool allows you to create a bootable USB or download an ISO image to burn to disc. In the case of a fresh install, if you are running Windows 7, the key from your existing COA will work as your key for Windows 10. With later versions of Windows where the key is embedded in the BIOS you should not be prompted for a key. There have been reports of Windows 7 keys not working for 10, but I've done hundreds of installs and have not experienced it personally. A workaround if you are concerned is to do the upgrade to Windows 10 first, which will activate your copy of 10 and bind it to your hardware ID and then perform a fresh install indicating you do not have a key and it will activate against that hardware ID again.
If you are doing an upgrade, MOST drivers will be retained and continue to work with 10. There are obviously exceptions, but generally this works. This means that if you are doing a fresh install and are concerned because your OEM may only have 7, 8 or 8.1 drivers, you can safely assume that you will be able to download and use those and it is prudent to do that beforehand and put them on a USB stick in case you end up needing them for network connectivity. It's a good idea to open Device Manager and expand the Network Connections area to ensure you grab the right network controller drivers as many OEM's will have more than one LAN and WLAN option depending on how the unit was shipped. This is also the case for Display Adapters, where there is often more than one option.
On a fresh install, older Intel chipsets will have generic support like "Standard AHCI controller" and the like and you will need to find your Intel Chipset drivers on your OEM's website, as intel has either buried or removed their universal 9.x-series drivers from their website at this time.
ATI/AMD Video drivers: https://www.amd.com/en/support
- If you don't see a Windows 10 driver, just choose the one for the latest OS that is supported, say Windows 8/8.1 or 7.
NVidia Video drivers: https://www.geforce.com/drivers
- Same note as for the AMD/ATI drivers.
HP/Compaq support website: https://support.hp.com/ca-en/drivers
If your computer is manufactured by HP/Compaq, you may find that some of the drivers won't install, yielding a red "blocked by Administrator" box. This is easily circumvented by downloading 7Zip from: https://www.7-zip.org/
and once that is installed, right-clicking the package, going to the 7Zip menu and extracting it. You'll then be able to run the setup that was contained within the archive.
A number of the OEM's, particularly DELL and HP have released very recent BIOS upgrades that include improvements for Windows 10. Also, if you are doing a fresh install from a system that contained Windows 7, you may want to go into your BIOS and change the operating mode from legacy to UEFI.
If you find yourself in a situation where you have a device in Device Manager that doesn't have a driver and you don't know what it is you can right-click it, go to properties -> Details -> Hardware Id's, then right-click and copy the 2nd one down (without the revision) and paste that into Google. That'll typically point you in the right direction. Careful what sites you click on! You don't want to get duped into installing some "driver wizard" or "driver update tool", look for a link from an OEM like HP, DELL, Lenovo, ASUS....etc.
If you want to skip using the tool and just get an ISO image, these can be obtained from here: Windows 10 IOS images