Lost Explorer after Critical Update to SBS2K

I have a Windows 2000 Small Business Server. I needed to run the Windows Update to bring the Server IE up to Version 6.1. I did this and unfortunately I have now got a problem with the Windows Explorer window. It blanks out the left pane and will only allow me to see the right hand pane. Also, I am no longer able to use the Add/Remove programs button in the Control Panel. If I try to open it, it just does nothing.
I have been searching for weeks to try and find an answer. So hope you guys can help me.