Try this response from Ramesh:
It's removed in XP SP2. To get back the functionality:
Download:
http://www.mvps.org/winhelp2002/alexa.zip
Unzip, place "related.htm" into your "\WINDOWS\Web" folder
Right-click on "RestoreAlexa.reg", select: Merge, and reboot.
-or-
For Pre- XP SP2 systems, type regsvr32 /i shdocvw.dll in Start,Run to
get
the extension back. If you're using Ad-aware, add the Related
extension to
exclusion list.
If you are using the first option and for some strange reason, you do
not have a right-click Merge option for .reg files, then just run
Regedit and Import the file.
Start-Run-Regedit
Use the menu option Registry-Import
....Alan