If you've got an old gaming PC that you've been using to do some casual to moderate gaming on, I hate to break it to you, but Valve needs you to change.
Specifically, Valve needs you to drop Windows 7 and Windows 8 and upgrade to at least Windows 10 if you want to keep using Steam as your one-stop gaming shop after this year.
According to a new Steam Support update, "Steam will officially stop supporting the Windows 7, Windows 8 and Windows 8.1 operating systems," effective January 1, 2024. "After that date, the Steam Client will no longer run on those versions of Windows. In order to continue running Steam and any games or other products purchased through Steam, users will need to update to a more recent version of Windows."
The issue is that new features in the Steam frontend rely on an embedded Google Chrome instance, and since Google Chrome has sunset its technical and security support for those operating systems, Valve will have to ditch those OS versions as well.
As for how many gamers this will affect, Steam Hardware Survey reports that only 1.86% of all Steam users use Windows 7 or Windows 8. There are more Mac Gamers than there are Windows 7 and 8 gamers, so this really isn't going to be that big of a blow to the user base, but for those who are affected, you do at least have til the end of the year to migrate to Windows 10 or later.
You really, really need to stop using anything older than Windows 10
So there is inevitably some frustration with a software-hardware lifecycle when the product you are using works just fine, thank you very much, and then someone comes along and makes you buy an upgrade that you don't really think you want or need.
In the case of Windows 7 and Windows 8, this isn't a matter of trying to upsell you on a new OS, it's really a matter of safety. Microsoft has discontinued its own security and technical support for these operating systems except for rare instances of long-term support contracts, which really don't have much time left in them either.
Microsoft doesn't have the resources to keep these older OS versions updated against the latest security threats, so using these operating systems puts you, as the user, at considerable risk. It might suck that Valve is threatening to cut you off from the games you paid for, but with less than 2% of users still on those versions of Windows, it doesn't make sense for Valve to do otherwise.
It's time, folks. It's time.