IE5 does not work after upgrading….

Ie5 does not work after upgrading from Ie4. This is after Sp4 was upgraded to Sp6a in the same session.
Ie5 will not accept any settings-

some error messages recieved from troubleshooting:
cannot find server-
access denied-
could not find (URL)-

and at times Ie5 would not open at all-

any suggestions?
thx
blb