In Vista Microsoft introduced a capability intended to alleviate DLL Hell. I guess it did but it introduced a new problem.
I first observed the winsxs problem on my daughter's Vista ThinkPad. Her husband had tried repeatedly to install an anti-virus. You'll recall that anti-virus vendors had problems early on with Vista. The result of these repeated installs was a hugely bloated winsxs directory. A clean of Windows 7 fixed that.
But the problem didn't go away. When I build my T420s I began tracking the growth in winsxs. It went from 10GB immediately after install to over 16GB after 20 months.
I wasn't the only one noticing this. Here are a collection of articles on this problem.
- How to reduce size of C:\Windows\winsxs folder in windows 2008 R2? (requires login)
- How to reduce the size of winsxs in windows 7 ultimate x64 (requires login)
- Engineering Windows 7 / Disk Space / Steven Sinofsky (yes, THAT Steven Sinofsky)
- Cleanup Winsxs after Windows 7 SP1 install
In the October 2013 patches, Microsoft quietly slipped in an update that helps.
Update is available that enables you to delete outdated Windows updates by using a new option in the Disk Cleanup wizard in Windows 7 SP1The steps on how to recover the disk space are here. My winsxs went down from 16.1GB to 10.8GB on my 120GB SSD. Even better I saved over 7GB on my X100e's 60GB SSD.
Make sure that your system is stable before you do this. Afterwards you can't uninstall any previous updates.
It takes a reboot to realize the savings.