Read Part 1 of this article, or continue to Part 3
In the last issue you learned that the HKEY_CURRENT_USER hive stores settings for the currently logged on user and the HKEY_LOCAL_MACHINE hive stores settings that apply to all users.
When you install software on your computer settings for that software are often times stored in the registry. This isn't the best solution because registry corruption can render programs useless. Another problem is that programs writing to the registry could possibly overwrite an important entry rendering the computer unbootable. Microsoft has tried to eliminate this in Vista by providing a specific directory (c:\program data) for software authors to store program settings and information.
Software is either installed for a specific user or for all users of the computer. It is a 50/50 change whether software will be installed for the current user, or all users, though some programs allow you to choose. Navigate by clicking the "+" or triangle beside each hive to HKEY_CURRENT_USER>SOFTWARE
Here you will see quite a few of the programs you have installed on your computer. Each of the entries in this tree is a software author. If you have more than one program installed from the same author you will find entries for each under the software author's folder. Settings in this tree will be user specific.
Scroll down to the Microsoft entry and expand (HKEY_CURRENT_USER>SOFTWARE>MICROSOFT). Very interesting to note that Microsoft lists most of the programs and features of the OS here. Windows itself is listed under the Microsoft folder. Feel free to have a look around.
Ok, Let's check out the HKEY_LOCAL_MACHINE hive. Click the "-" or tilted triangle next to all entries you have expanded to close them. Click the "+" or triangle next to HKEY_LOCAL_MACHINE to expand the tree and scroll down to software. You will notice there are many similar entries and quite a few that don't show in HKEY_CURRENT_USER.
Scroll down to Microsoft and expand the tree (HKEY_LOCAL_MACHINE>SOFTWARE>MICROSOFT). Scroll down again to Windows (HKEY_LOCAL_MACHINE>SOFTWARE>MICROSOFT>WINDOWS) and expand. CurrentVersion should be the first entry (HKEY_LOCAL_MACHINE>SOFTWARE>MICROSOFT>WINDOWS>CurrentVersion). Here is where you will find most settings that control Windows appearance and function.
Most entries are self explanatory. Control Panel contains settings for the Control Panel, Run contains settings that cause programs to run at startup, Uninstall will contain the uninstallation strings for most programs, etc. Have a look around. You will be surprised at what may look familiar. The next time you make a settings change you'll have a better idea of what is going on behind the scenes.