I have two machines - a desktop and a laptop.
I am not sure if this is relevant, but I had previously downloaded IE7 Beta, and forgot to uninstall it.
I then upgraded Windows XP Home to Windows XP Professional, and as soon as I did it, I get the following error message on the desktop machine when I started to use IE.
"The procedure entry point InternetGetSecurityInfoByURLW could not be located in dunamic link library WININET.dll"
Microsoft Help firstly tried sfc /scannow and then did a Windows repair but still not working.
On the laptop, I now have IE6, but I get another instance running when I change urls, but the second one hangs.