JDiskReport

There are lots of software tools out available that can help you understand how the space on your drive is being used. I always try to put the largest drive possible in any computer I own. Still there are times when space available runs a bit low and I need to figure out what I should delete or perhaps move off another drive. Whenever this happens on Windows, I tend to gravitate back to using JDiskReport.

Once installed you will be presented with the JDiskReport page letting you choose what drive or directory path you want to report on.

Once the scan is complete you will be presented with a report that you can analyze. 

The two areas I typically focus on first are:
1)  Which folder is taking up the most space.  You can easily tell by viewing the pie chart.  You can drill down as necessary.

 2)  The Top 50 largest files.

After analyzing these and cleaning up whatever I don't need or want, I might rerun the report if I deleted a lot of files.  Otherwise, I would take a quick look for anything unusual.