Setting it up
First, make sure you're running Windows 2000, XP, or newer. But not those fancy 64-bit versions, cause it doesn't work.
Download the installer.
Run the downloaded file to start the install wizard. It has boring template text, so just keep clicking Next.
Now the Folder Size column is available to Explorer, but Explorer isn't displaying it yet. Open an Explorer window in Details view.
Right click on the column headers to see a list of columns you can add. Choose Folder Size.
Now we can replace the existing Size column with the new Folder Size column. Right click on the column headers and uncheck the Size column. Drag the Folder Size column header to where Size used to be.
Make this the default view for all folders. Go to Folder Options from the Tools menu. In the View tab, click Apply to All Folders.
Look in the Windows Control Panels to find the Folder Size control panel. If you're in the confusing Category View in XP, where it says Pick a category, click on Switch to Classic View in the left-hand pane. And then view as Icons. Isn't that better?
Use the control panel to change the way sizes are displayed. Also stop the service to stop any background activity.
So it crashes every once in a while, and slows down your computer. That's no reason to uninstall it. Well, if you really want to, use the Add/Remove Programs control panel. You'll have to manually fix the columns in Explorer too.