OK, it depends, as to u may be Eiditng registyry seems easy, anyway, here is how u may do it,
Navigate to,
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
if u see any key as ,
Window Title then Delete that

it should solve the Issue....
but it seems that ur IE7 installation source didnt come directly from Microsoft, so it may have security issue, thats why I suggested to un-install and then Re-install with Microsoft Download !!!