There are dozens of Registry tweaks and walkthroughs scattered around the pages of this site, and I'm not going to try to include them all here. Rather, I'm going to give an overview of what the Registry does, an idea of its overall structure, and some tweaks to provide better performance for your PC. I'm heavily indebted to the PC Magazine article of March 25, 2003, entitled Registry Tweaks for Better Performance, which can be found at www.pcmag.com/article2/0,4149,909988,00.asp, and include some information and tweaks that I've left out.

What exactly is the Registry? It first appeared in Windows 95 and NT, and is still a little-known, but essential, part of the Windows operating system. It controls just about everything Windows does: how it looks, how it works, and what you can and cannot do. We can access the Registry directly through REGEDIT (go through Start, Run and type REGEDIT), but doing so is akin to stepping off the tour bus and directly into the jungle. You can do it, and not only survive but even thrive and progress, but you'd better know what you're doing. If you're not comfortable with dealing with the Registry, then you're better off leaving it alone. Plenty of programs out there claim to "prune" and "clean out" the Registry; some of them are listed on my Disk, Maintenance, Hardware, and Diagnostic Utilities page. Be careful what you use and how you use it; some of these programs are strictly for the knowledgeable, and some can do unimaginable damage if used improperly.

There are five "root keys" that make up the Registry. They are:

• HKEY_CLASSES_ROOT= HKCR
• HKEY_CURRENT_USER= HKCU
• HKEY_LOCAL_MACHINE= HKLM
• HKEY_CURRENT_CONFIG= HKCC
• HKEY_USERS= HKU

Other subsidiary keys branch off of these root keys. These subsidiary keys are what we will be working with. Before you make any changes using Regedit (i.e. after you highlight a key and before you change anything), back up its current contents by selecting Export from the Registry menu. The .REG file that is subsequently created is your insurance policy; you can add descriptive comments to the .REG file if you like, just remember to start your comment lines with a semi-colon (;). If a tweak doesn't work, launch the .REG file (by double-clicking it) to undo your changes.

If you want to know more specifics about how the Registry operates, check the following sites: www.annoyances.org/, regedit.com/, newbieclub.com/rfncopy/?infopackets, members.aol.com/Knows98/regtips.htm, www.winguides.com/guides.php?guide=registry, and www.woram.com/.

Back up the XP Registry by going to REGEDIT (go to Start, Run, and type in "regedit" without the quotes.) Click on the registry key that you are going to edit. Go to File and click Export. Choose a location to save the registry key file and click Save.

Windows XP has a vast number of configuration dialogs, but some adjustments can be performed only by directly editing the Registry. The Windows XP Backup applet can back up the Registry along with other elements of the System State, but the resulting data file can occupy hundreds of megabytes. You're better off saving a system restore point each time you're about to edit the Registry. Better still, you can use Regedit to back up only the Registry keys that will be changed. Click on Start, Run and enter Regedit to launch the Registry editor. To back up an individual key you plan to edit, navigate to the key and right-click on it. Choose Export from the menu, and save the key to a REG file. Open the REG file in Notepad and insert a few comment lines that describe the source and purpose of the tweak. (To create a comment line, simply put a semicolon at the start of the line.) Now go ahead and make all the changes to Registry keys and values specified by the tip you're applying. Any time you add a new key or value, make a note of it with another comment line in the REG file. When you're done, save the REG file and close Notepad. If later you want to undo this Registry tweak, just double-click on the REG file and confirm that you want to add it to the Registry. This will restore any deleted keys or values and will restore the original data for any values whose data was changed. Note that this will not remove new keys or values that were added; that's why you need to make comments about such changes. Right-click on the REG file and choose Edit, which will open it in Notepad. Check for comments about keys or values that were added, and if you find any, use Regedit to delete them. You can delete the REG file itself once you've completed this process.

Let's get into some tweaking, whaddya say? Rules of thumb: if the tweak calls for a specific key or value to be changed and that key or value doesn't exist at all, you can simply add it. You may need to log off and restart your computer for some changes to take effect. My advice: restart after every Registry tweak, don't try to make a number of changes and then restart, leaving Windows to handle a multiplicity of changes.

In all cases cited below, when the Registry uses strings of digits and numbers, it uses zeroes and not upper-case O's.

• MultiColumn Start Menu: If you don't like your Start menu displaying only part of its contents, with arrows leading up and/or down to more items, and you'd prefer multiple columns displayed, here's how to do it:
  HKCU \ Software \ Microsoft \ Windows \ Current Version \ Explorer \ Advanced -- if you're running MSIE 6, change the StartMenuScrollPrograms string value to NO; if you're running another version of MSIE, change the string value to FALSE.
• Customize Internet Explorer 4x and Later: The animated display in the right corner of IE (or Outlook Express) that displays while the browser is busy can be changed. It's a simple bitmap (.BMP) image after all. This tweak also removes or changes the branding string added to the window title. (If you hate the changes, restore the defaults by removing the five values added below.) For custom animated images, create or provide a 20x20-pixel and 38x38-pixel static bitmap images. Now create, or provide, multiple 20x20 bitmaps, with each successive frame of animation positioned below the previous one. Then do the same with a 38x38-pixel animated image, and make the following Registry tweak:
  HKCU \ Software \ Microsoft \ Internet Explorer \ Toolbar -- change the BigBitmap string value to the name of the large (38x38) static bitmap file. Change the SmallBitmap string value to the name of the smaller static bitmap file. Change the BrandBitmap string value to the name of the large animated bitmap. Change the SmBrandBitmap string value to the name of the small animated bitmap.
  HKCU \ Software \ Microsoft \Internet Explorer \ Main -- in WindowTitle, change the string value to the desired window title.
• Add a Log-On Notification: This provides a message at logon; i.e. a notification of company policy, a romantic little goodie for your honey in the morning, or whatever. Compose the text as a single paragraph in Notepad, then add it like so:
  In Windows 9x/ME:
  HKLM \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Winlogon -- change the LegalNoticeCaption to your desired caption, and the LegalNoticeText to your desired text.
  In Windows NT/2K/XP:
  HKLM \ SOFTWARE \ Microsoft \ WindowsNT \ CurrentVersion \ Winlogon -- change the LegalNoticeCaption to your desired caption, and the LegalNoticeText to your desired text.
   
• Use Custom Drive Icons: In the tweak below, replace the word drive with the drive letter, and specify the path name of the icon file. If the file is an .EXE or .DLL file rather than an .ICO file, append a comma and the index of the icon within the file, like so: C:\WINDOWS\SYSTEM\SHELL32.DLL,13 for one example. Note: this tweak only works on Win 95 and NT systems if they've had the IE 4 Desktop Update included, and doesn't always work with Win 2K and XP.
  In Windows 9x/ME/NT:
  HKLM \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ explorer \ driveicons \ drive \ DefaultIcon -- change the string value (Default) to whatever your desired icon is.
  In Windows 2K/XP: HKCR \ Applications \ explorer.exe \ Drives \ drive \ DefaultIcon -- change the string value (Default) to whatever your desired icon is.
   
• Noncentered Wallpaper: Along with the usual Display Properties choices of Center, Tile, and Stretch, this gives you the option to show a full-sized image off-center; you need to supply X and Y coordinates of the top left-hand corner.
  HKCU \ Control Panel \ Desktop -- change the string value of WallPaperOriginX to your desired X coordinate, and the string value of WallPaperOriginY to your desired Y coordinate.
• Change the Recycle Bin Icon: You can change both the "empty" and "full" icons. As in the above example, if you're using an .EXE or .DLL file instead of an .ICO, you need to append a comma and the index of the icon within the file.
  HKCR \ CLSID \ {645FF040-5081-101B-9F08-00AA002F954E} -- change the string value (Default) to the new icon title.
  HKCR \ CLSID \ {645FF040-5081-101B-9F08-00AA002F954E} \ DefaultIcon -- change the string value (Default) to the icon for the empty bin. Change the Empty string value to the icon for the empty bin. Change the Full string value to the icon for the full bin.
• Control the Way Applications 'Take Focus:' Normally, when a background application wants to grab your attention, the default action is for the taskbar button to flash three times and then wait for you to click it. With this tweak, you can change the number of flashes or let background applications take focus immediately (the equivalent of shoving the currently active app aside in favor of the new app).
  HKCU \ Control Panel \ Desktop -- change the ForegroundFlashCount DWORD value to whatever number suits you (0 for infinite flashes). Change the ForegroundLockTimeout DWORD value to whatever you like; 0 is infinite, 200000 is the default. (Note: a reader tells me that the DWORD value of 0 is not infinite, but instead is simply 0, i.e. no flashes. Thanks for the tip!)