As of writing this we're 3 days away from the official end of life for Windows 7. You can keep using it, and receive security updates. You can also still "upgrade" to Windows 10 for free.
Windows 7 Installation guide
As it happens I just installed a fresh copy of Windows 7 on a rebuilt system today. This guide will work for any edition - including Upgrade editions. Before we begin you will need to register accounts on the My Digital Life and Seven Forums (/Ten Forums). Do not trust any 3rd party tools or downloads not endorsed by one of those forums - and do not get download links from elsewhere. I suggest using VirusTotal to ensure any 3rd party downloads are safe. Here are the steps:
Installation media
Make sure you have SP1 installation media. My copy has the original pre-SP1 discs - if that's what you have download the SP1 version here (or directly from Microsoft). If you're burning to DVD-R just use ImgBurn, otherwise if you're using a USB use Microsoft's tool (you'll be able to select the ISO file you downloaded). If you have an upgrade edition don't enter your product key during install, see below.
Install and disable Windows update.
Activation
OEM versions. If you have a branded system like Lenovo, Dell, etc and you don't want to use the sticker product key you can backup and restore the OEM information, there are a number of tools to help with this (completely offline pre-activation), so I'm not going to bother explaining the process.
Product Key. If you open the System dialogue you can click "Activate Windows". Enter your product key, if it's an OEM version it's highly likely you'll have to use phone activation, otherwise activation should be automatic.
Upgrade editions. If you have an upgrade version of Windows 7 and installed completely fresh, you probably have this error (0xC004F061):
Don't worry about previous installation media or keys, we can activate the system in two steps. (1.) Open a command window with administrator privileges (winkey+R "cmd"). Enter these commands:
Restart the system. (2.) Open up a command window with administrator privileges, and enter this command:
slmgr -ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
Where xxxxx-xxxxx-xxxxx-xxxxx-xxxxx is your upgrade product key, obviously. Open up the System dialogue and click Activate Windows if present - if online activation fails use telephone activation.
Existing Installations: Update Windows
As I mentioned earlier, it's now advisable to keep Windows Update permanently disabled. On the other hand you absolutely need updates. Start with this package (whether it's a fresh installation or an old installation). Ideally you should re-download every month to install new updates. You will also need the Microsoft Visual C++ Redistributable. After that you can install an AntiVirus program of your choice.
Bypass Windows 7 ESU
You need to bypass Windows 7 ESU to ensure you can continue installing security updates. The app for that is here. That on its own won't get you any ESU updates, you'll have to check that forum thread to see how to get them in the future.
Windows 7 Installation guide
As it happens I just installed a fresh copy of Windows 7 on a rebuilt system today. This guide will work for any edition - including Upgrade editions. Before we begin you will need to register accounts on the My Digital Life and Seven Forums (/Ten Forums). Do not trust any 3rd party tools or downloads not endorsed by one of those forums - and do not get download links from elsewhere. I suggest using VirusTotal to ensure any 3rd party downloads are safe. Here are the steps:
Installation media
Make sure you have SP1 installation media. My copy has the original pre-SP1 discs - if that's what you have download the SP1 version here (or directly from Microsoft). If you're burning to DVD-R just use ImgBurn, otherwise if you're using a USB use Microsoft's tool (you'll be able to select the ISO file you downloaded). If you have an upgrade edition don't enter your product key during install, see below.
Install and disable Windows update.
Activation
OEM versions. If you have a branded system like Lenovo, Dell, etc and you don't want to use the sticker product key you can backup and restore the OEM information, there are a number of tools to help with this (completely offline pre-activation), so I'm not going to bother explaining the process.
Product Key. If you open the System dialogue you can click "Activate Windows". Enter your product key, if it's an OEM version it's highly likely you'll have to use phone activation, otherwise activation should be automatic.
Upgrade editions. If you have an upgrade version of Windows 7 and installed completely fresh, you probably have this error (0xC004F061):
Don't worry about previous installation media or keys, we can activate the system in two steps. (1.) Open a command window with administrator privileges (winkey+R "cmd"). Enter these commands:
Code:
REG ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\OOBE /V MediaBootInstall /T REG_DWORD /D 0 /F
slmgr /rearm
Restart the system. (2.) Open up a command window with administrator privileges, and enter this command:
slmgr -ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
Where xxxxx-xxxxx-xxxxx-xxxxx-xxxxx is your upgrade product key, obviously. Open up the System dialogue and click Activate Windows if present - if online activation fails use telephone activation.
Existing Installations: Update Windows
As I mentioned earlier, it's now advisable to keep Windows Update permanently disabled. On the other hand you absolutely need updates. Start with this package (whether it's a fresh installation or an old installation). Ideally you should re-download every month to install new updates. You will also need the Microsoft Visual C++ Redistributable. After that you can install an AntiVirus program of your choice.
Bypass Windows 7 ESU
You need to bypass Windows 7 ESU to ensure you can continue installing security updates. The app for that is here. That on its own won't get you any ESU updates, you'll have to check that forum thread to see how to get them in the future.