I customized it once, then couldn’t remember the name of it to figure out how to do it again. It took an hour to figure the name out. What is the Places Bar, you ask?
When you save or open a file in an application that uses Windows XP’s common dialog box, chances are that you use the Places bar on the left side of the dialog box to speed up your navigation. It shows up to five places, such as “My Documents” or “My Computer”, that you can to quickly go by clicking on them.
As explained in this mvps.org article, you can customize the Places bar three ways: by editing the local group policy with the Group Policy Editor, by editing the registry entry “HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ comdlg32 \ Placesbar”, or by using TweakUI. The easiest and best way is to use the MS Powertoys program TweakUI. Go to its Common Dialogs, select custom places bar and change at will.
TweakUI is a must-have with so many features that I sometimes forget they exist, as in this case. If you don’t have it, go to Microsoft PowerToys for Windows XP and get it. The “ClearType Tuner” available on the same page is also a nice addition, especially on LCD displays.