I just checked mine and it is at 33 GB. Are you running a fresh installation? Do you have very many MS development tools installed?

I know in the past, any Windows updates would be cached in your windows directory forever and there was no safe way to remove them. That would gradually grow the windows directory size forever. Also, it seems there are a lot of files that get thrown in there when you start installing multiple versions of SQL Server or Visual Studio.

Right-click on the drive -> Properties -> General.

Disk Clean-up.

Clean-up System Files.

Windows Update Clean-up (and Temporary Windows installation files).

Ok. Ok.

Enjoy.

I did a clean install of Windows 10 on my workstation less than a month ago and my Windows directory is sitting at 23GB, methinks something funky is going on here.

Do you have a bunch of applications installed? IIUC, Windows keeps different versions of each of its DLLs around for whatever apps requires them. I would expect that installing applications might embiggen your Windows directly a lot.

I wouldn't say I have "a lot" of applications installed, although I'm not too sure how to quantify that.

I assumed it WinSxS related as the other reply mentions, and upon investigation found that it is 9GB alone! I don't run Windows outside of work so I've just never really bothered looking into it, but if it continues to balloon I guess I'll have to.

It's probably due to WoW64 and WinSxS inflating due to dll caching and backup resources after Windows Update.