Microsoft has released an optional update (KB2852386) for Windows 7 SP1 that adds a function to Disk Cleanup, allowing you to scan for and remove leftovers from previously applied updates and patches. This can reduce the size of your WinSxS folder significantly. On my rather fresh Win7 SP1 install (it's a little under a month old now) that was based on an image I made using sysprep and the latest updates, Disk Cleanup was able to remove around 500mb from the WinSxS folder. On typical Win7 SP1 installs the amount of data that can thus be removed will be significantly greater than that -- probably more around 1.5 to 3 gb. Many people have requested a feature or app like this for years (Vista had one) and it would seem the requests did not fall on deaf ears. Windows 8 and 8.1 already have this feature so seeing it in Win7 would make one think it is yet another backport of a Win8 feature to Win7. I would imagine this would also work when making images via sysprep, as it would allow you to clean out WinSxS before applying sysprep, which should make the resulting Win7 SP1 image smaller (I'm thinking around 100/120mb for the install.wim). Soon I'll test it when I make updated images via sysprep again and will mention my findings here in this thread. Read more about this update here and here. Download x86 version Download x64 version Note: If you try to download certain updates from the Microsoft site with any other browser than IE 32-bit, it will offer you to download the GenuineCheck.exe to produce a code to allow you to download. That validation method doesn't work anymore, so if you want to download updates from the Microsoft site directly it is necessary to use IE 32-bit.
cool, I know alot of people have been asking for this nice to see that they were working on it, I know many were doing this manually.
Follow up: I did a Win7 x64 build via sysprep with latest update batch and I think only 100mb got cleaned out, which will mean less on the final install.wim (due to its compression). But, that is if you have a really tight update collection where you keep track of superseded updates, or the amount might be quite a bit bigger. So this function will be useful more for older installs where many updates have been applied on top of each other, live, as in such a situation WinSxS will keep copies of each file version and update and this will have the effect of WinSxS growing. Still, quite nice I did, however, notice a small flaw: KB2446710 is an older update that is technically superseded, but is still getting offered by WU even if the superseding update is installed. So it is what could be called a 'WU-satisfy' update. When KB2446710 is installed and Disk Cleanup is run to remove old update files, it deletes 60mb of stuff, after which KB2446710 gets offered in WU again. Etc... So that's a bit annoying.
