Thanks.
Wouldn't believe it if I didn't see it with my own eyes. Opening a new window by double clicking IE icon, pressing CTRL-N, or selecting File|New|Window
=
current window vanishes, new window opens, can not click back button to return to previous page.
Followed instructions in Microsoft Knowledge Base Article - 281679 (
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q281679) "You cannot open a new Internet Explorer window or nothing occurs after you click a link" up to re-installing (upgrading) XP.
Finally checked add-remove programs and found Yahoo Toolbar installed MANY MONTHS ago. Uninstalled it. Problem solved.
If it helps, the last thing I did before the problem started was install the latest version of Macromedia Shockwave. (recommended by visiting
www.boardsofcanada.com band site).
Oh, and don't forget the candles and incense, always helps in these situations