A friend asked me about this utility again so I thought I would mention it here. This will help him to more easily find later and maybe help some others as well. I have used this utility for years now and it is the only one that I know of that does this in a single file executable that requires no installation.

Working in a server environment, there are times when the issue at hand is a lack of free space. Oft times, where that space is being taken up is not easily identifiable which makes it a pain to troubleshoot rapidly. When that happens, I have found this little utility called Scanner to be immensely useful in identifying probable sources of these space vampires.

From the description

This tool uses a unique concentric pie chart to display the usage of your hard disk or other media. The chart shows all major files and folders from all directory levels at once.

The last version was updated in 2006. It is a single file executable with no install needed (it's not the fastest but that's OK) and it works on mapped network drives. It most beneficial use is in finding the huge files buried deep in obscure directories.

The the most memorable use I found for it was on an Exchange 5.5 server that was rapidly running out of drive space on the database drive (a very very bad thing). Using this scanner utility we were able to find that the Trend anti-virus definition files were not clearing themselves out properly and were consuming over 3.5 GB worth of disk space. Another example was a drive alert on the C: drive of a server that multiple people had recently logged into. It turned out that someone had saved the service pack files to their desktop (don't do that) and as it was the default desktop, every time someone logged in it was getting copied to that new desktop. Service pack 350 MB, 6 people log in = 2.1 GB of used space in a short period of time.

I hope others will find the utility as useful as I have.