[HOW-TO] Free disk space being used for Windows Installer data files
At the office where I work over the summer, one of my responsibilities is performing basic computer maintenance. I encountered one Windows XP computer that only had about 2GB of free space left on an 80GB capacity hard disk. Even after running a cleanup with CCleaner and scanning for malware, there was no significant change in free space. The computer’s owner only had about 4GB of her own data and not many applications were installed. I got suspicious and ran Free Disk Usage Analyzer only to find out that Windows was the culprit. After running a cleanup with msizap.exe, I was able to recover over 50GB of free space! How awesome is that?!
The disk usage analyzer showed me that C:/WINDOWS/Installer/ was occupying about 50GB worth of space on the drive. I found this quite surprising, since I had never encountered that folder or knew it could grow so large. After a bit of searching around on Google, I came across the Windows Installer Cleanup Utility. It’s one of those tools that you will not easily find on the Microsoft website, but it solved this problem easily. Here are the steps you can take to gain more space on your disk.
- Download the Windows Installer Cleanup Utility and run the installer. The corresponding entry is placed on your Programs menu, but we won’t be accessing it via this route.
- Launch a command prompt by going to Start > Run > cmd and press ENTER.
- You need to enter ‘C:/Program Files/Windows Installer Cleanup’ via the command prompt.
cd C:\Program Files\Windows Installer Clean Up
- Enter the following command and press ENTER.
- Exit the command prompt and re-check the size of C:/WINDOWS/Installer/.
The G parameter instructs msizap.exe to clean up orphaned files, which happened to be the cause of the heavy disk space usage. The exclamation mark suppresses confirmation prompts.
On normally-functioning Windows PCs, running this tool will usually have no effect since there is no significant inflation of C:/WINDOWS/Installer/. However, if you notice that the directory’s size is unusually large, it’s not a bad idea to run it to see what can be cleaned up.