Win 2K Professional and SP4

Installed SP4 in a working system. Once installed, IE 6.0
refused to initialize. Could not establish a web
connection usinf IE 6.0 AOL 6.0 worked fine. Tried to
install SP4 at least twice, with the same results. Have
returned my system to SP3 configuration and, as before, it
works fine.

Any help or suggestions would be appreciated.

Thanks

Klaus