My colleague Brian Hitney (creator of WorldMaps) offers a great tip on Volume Shadow Copy, and how to get back some of the space it uses for backing up files (the usual caveats about risks of disabling such features apply):
I've spent a lot of time talking about Vista internals at various groups ... and, I admit it, I haven't blogged too much about some of the tips I give in this talk. So, I'd like to give a tip about Volume Shadow Copy.
Volume Shadow Copy originally appeared, I believe, in Windows XP. It was used as a way to get reliable backup copies of files, since backup applications couldn't necessarily get reliable snapshots of files that were in use. This functionality was exposed in a new way in Windows 2003, where XP clients would see a Previous Versions tab on their shared folders that lived on the server.
In Vista, Volume Shadow Copy is used for both system restore and for Windows Backup. It creates snapshots of your files so if there are accidental changes or deletes, they can be recovered. While this is a great feature, I don't want it crowding space on my laptop. I keep backups elsewhere.
If you drop to a command prompt (run as administrator) you can see how much space is currently being used by typing:
c:\>vssadmin list shadowstorage
It will return the amount of space used, reserved, and maximum allocated. If you want to reduce this footprint and reclaim some serious space, you can type something like:
c:\>vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=500MB
Now, 500MB is pretty small and you'll likely lose some restore/backup capability at this size, but as a do-it-yourself kind of hacker, I'm willing to take that risk as space is a premium on my laptop.
And if you haven't used Volume Shadow Copy, it's a great way to keep versions of your files. Check it out!
Again, you should probably only try this if you've got a good backup strategy in place, but on my system, Volume Shadow Copy was using over 11GB of space...that's a significant chunk of real estate if you're already backing up elsewhere.
Speaking of which, I finally got a chance to use the built-in imaging functionality of Windows Vista, and I have to say it rocks, and is very easy to use. The main use for the tools (such as ImageX, described here), is to create and automate the deployment IT-standard installs of Windows Vista. But you can also use ImageX to create an image of your day-to-day system, and back that image up to an external hard drive, another machine, or somewhere else that you have space. Then, if your OS were to become corrupted, you can just restore the entire image. Note that if you're planning to do this, it becomes imperative to maintain a clean separation between OS and programs, on the one hand, and data on the other. And the best part is that the tools to create images based on the ImageX format (WIM) are available at no additional cost.