Microsoft only supports every version of Windows for so long. For example, Windows 7 is currently in "extended support" until January 14, 2020, after which Microsoft no longer supports it. This means that.
No more security updates
When Microsoft stops supporting a version of Windows, Microsoft stops issuing security updates for the operating system. For example, Windows Vista and Windows XP no longer have security updates, even if there are major security holes in them.
January 14, 2020, the same will apply to Windows 7. Although people discover major security holes affecting Windows 7, Microsoft will not provide you with security updates. You are yourself.
Certainly you can run anti-virus tools and other security software to try to protect yourself, but antivirus is never perfect. Running software with the latest security updates is also important. Antivirus is just a layer of defense. And even security programs will gradually release support for older versions of Windows.
Microsoft continues to make security updates for Windows 7, even if you can not get them. Larger organizations can sign "Custom Support" contracts to continue to receive security updates for a period while switching to a new operating system. Microsoft speaks up the price forward to encourage those organizations to actually move to a new version of Windows. The same thing happened to Windows XP.
RELATED: Microsoft still does security updates for Windows XP, but you can not get them
Software companies stop supporting it, For
When Microsoft stops supporting an operating system, it is also a signal to other software companies and hardware companies. They will stop supporting the older version of Windows with their own software and hardware.
This does not always happen immediately, but it will eventually happen. For example, Windows XP support ended April 8, 2014. However, Chrome did not stop supporting Windows XP until April 2016, two years later. Mozilla Firefox stopped supporting Windows XP in June 2018. Steam will officially release support for Windows XP and Windows Vista on January 1, 2019.
It may take a few years as it did with Windows XP but third-party applications will  Windows XP One more: Windows XP One, Windows XP One End Support is April 8, 2014: Why Windows Alerts You
New Hardware May Not Work
New Hardware Components and peripherals will stop working on your system. These require hard drive drivers, and manufacturers may not create these hard disk drivers for your old, old operating system.
The latest Intel CPU platforms do not even support Windows 7 and 8.1 right now, although these operating systems are still technically in "extended support" today. It's already starting, and Microsoft still supports Windows 7!
Certainly, you can continue using your old operating system with your current software and hardware, but you have no guarantee of future updates or compatibility.
: How (and Why) Microsoft Block Windows 7 Updates on New Computers
When will Microsoft end support?
Microsoft defines deadline for support before time so they are never a surprise. You can see all dates on Microsoft's life cycle in Microsoft, so you know exactly how long Microsoft will support your version of Windows with security updates.
Give Microsoft some credit here. At least Microsoft has an official policy. Apple just stops supporting old MacOS versions when it feels like it, without a clear policy.
RELATED: How long will Microsoft support my version of Windows with security updates?
Technically, there are several types of "support".
Common consumer versions of Windows 10, that is, Windows 10 Home and Windows 10 Pro -Receive feature updates every six months. These updates are then "service" for 18 months. This means that they receive security updates for eighteen months, but you can always get more security updates by updating to the next release. However, Windows 10 installs these new versions.
If you still use Windows 10's Creators Update for some reason, Microsoft stopped supporting it on October 9, 2018, because it was released April 5, 2017.  Enterprise using Enterprise and Education editions is able to use some of these updates anymore. In Windows 10, they are "serviced" longer. Organizations using Windows 10 LTSB have even longer support periods.
Things are a bit different with older versions of Windows. Windows 7 left "mainstream support" on January 13, 2015. This means that Microsoft has stopped non-security updates. In extended support, Windows 7 only receives security updates. They will end on January 14, 2020. (Note that Windows 7 will only receive security updates if you have installed Service Pack 1.)
Windows 8.1 left the standard support on January 9, 2018, providing extended support on January 10, 2023.  You should upgrade instead of using a non-supported Windows
We do not recommend using a Windows version that is no longer supported by Microsoft. It's just not sure.
We recommend upgrading to a newer version of Windows. Do not like Windows 10? Well, consider switching to Linux, try a Chromebook or buy a Mac.
By the way, while Windows 7 only has until January 14, 2020, you can still upgrade to Windows 10 for free from Windows 7 or 8 with this trick.
RELATED: You can still get Windows 10 for free with a Windows 7, 8, or 8.1 Key