Windows XP start menu Internet icons
The Windows XP Start Menu features, by default, two 'pinned' entries for your Web-browser and Email client. Personally, I use SeaMonkey for both. But, I'm not the greatest fan of the SeaMonkey icons, and I certainly don't want to use the same icon for both.
A quick search of the registry reveals these two locations:
* HKLM\SOFTWARE\Clients\StartMenu\Internet
* HKLM\SOFTWARE\Clients\Mail
Within these keys are sub-keys for all the registered browser and mail clients. If you expand your preferred application key you'll see a sub-key called "DefaultIcon".
Just change the (default) value in that key to the location of your icon (either just a path to the .ico, or a path comma index for a library (e.g. 'myicons.dll,4'))
You may need to repair your icons for this to refresh, you can do that using TweakUI