When i logon to the Internet it opens at my ISP's home page, overriding 'About Blank.'  I have deleted all the reg enteries I can find that migth allow this to happen, but to no avail. Any suggestions? Many thanks..

   Ask your ISP.  It could be something that only your ISP knows about.  Maybe they will tell you how to disable it.
   You might tell us which ISP it is.  That way if someone else has solve that, they can tell us.

Hello,
If you have not done so. On the IE Explorer page. Under the ( Tools ) drop down menu from the top of the page. Then click on (Internet  Options) Then, Under the tab (General) You should see the title (Home Page) and a  (Address) window which reads (You can change which page to use for your home page) or something similar.
Below the address window their are three options to select from (Use Current) (Use Default) (Use Blank) select one of these or enter your own information in the window.

There is a program, AboutBuster, to stop IE from loading with About:blank. It's available from a number of sources. Here is one:
http://www.majorgeeks.com/download4289.html