Dont forget

[Burgerman]

Windows stores hundreds of thousands of tiny files as a huge backup of prevous service packs in case you want roll back a major update.
They live here C:\Windows\servicing\LCU

If you want to delete the contents of this folder you can. If you do proper backups its pontless anyway.

I just deleted another 219,000 files.... They reappear every time after windows does a major update. Unless you want to roll back again they are not needed.

[Arima]

2gb recovered on the first machine I checked. Not a huge amount by todays standards but there is something satisfying about cleaning up unused files.

[Burgerman]

Its the sheer number of them that can make a machine slow on things like first opening a drive or copy operations etc. Not just the size though.

[Burgerman]

And theres 200,000 files!