KB Article: http://support.microsoft.com/kb/315352
After you upgrade Microsoft Windows 98 Second Edition or Microsoft Windows Millennium Edition to Microsoft Windows XP or Windows XP SP1, when you install a program on your Windows XP-based computer, you may receive an error message that is similar to the following:
Error 1606. Could not access network location <Common Administrative Tools>.All users\.
Additionally, nothing may occur when you try to open Administrative Tools in Control Panel.
I can't download updates because error 1606 appears