Windows Vista Cleanup

So this isn't a security post, but it still involves Windows and home PCs. Anyway, this past weekend I noticed Windows Update offering the SP2 upgrade for my system. SP1 has been out over a year and I haven't had any issues since I have 1) installed SP1, 2) a hardware firewall, 3) a software firewall, 4) current Antivirus software and 5) current Antispyware software. But I decided to install SP2 since eventually MS will require it to keep updating my system.

I started it in the morning and didn't check on it until later in the day. It failed after restarting the computer. It didn't say why, but reversed all the changes and restarted again. Huh? So I went back into Windows Update, clicked on the update history and right-clicked the update. Not enough disk space. Hmm. Well, I have a 250GB drive, but it is divided into a 30GB Vista system partition, 30GB Windows 7 Beta partition and the remainder is my data drive (which has plenty of free space). So how much space do you need to install SP2? 7GB for 32 bit, more for 64 bit. Oops! I was down to less than 1GB!

Using a free utility named TreeSize Free, I analyzed the disk space usage on C: (the Vista system) drive. The Windows folder was using 17GB alone. Really? That much? Under Windows, the Winsxs folder was using over 11GB. From my web research I discovered, Winsxs is the Windows side-by-side folder where Windows keeps multiple versions of DLLs for applications that require a specific version. It also appears to contain other things, but the conventional wisdom is to not delete the folder.

So, how do you recover 7GB of disk space in order to install SP2? Here's what I did:

1. Remove unused programs (and manually deleted their folders after restarting Windows)
2. Opened Internet Explorer and other browsers and deleted internet temporary files
3. Ran cleanmgr. This utility cleans up temporary Windows files.
4. Browsed through my profile and found multiple cached copies of temporary internet files not deleted using the browsers.
5. Ran the Windows Vista SP1 Disk Clean-up Tool, vsp1cln.exe. Note: You cannot uninstall SP1 after running this program which should be OK if you are installing SP2. This reduced the Winsxs folder size by about 1GB. Some have reported better results.
6. Deleted the "Windows\Software Distribution" folder. Windows Update will recreate as needed.
7. I have Ultimate, so I removed the Ultimate DreamScenes feature, then deleted the files after restarting.
8. Defragmented the C: drive.

This only got me about 5.5GB of space, so I've decided that rather than to continually fight the disk space battle with Vista, I am waiting until October 22 when Windows 7 is released. At that time, I will delete the existing Vista and Windows 7 Beta partitions and create a new single partition for Windows 7 RTM.
I know I bailed on the SP2 upgrade, but many others will not have the same extreme disk space contstraints and this information may prove useful. If you know of any other verifiable methods for increasing disk space, let me know.

Update:  Went back and deleted the 2nd partition and extended the Vista partition into it for a total of 60GB.  I now have plenty of space and have SP2 installed.  Goes to show how little I have played with Vista to not realize I could expand the partition sooner!