NSW 2004 NPF 2004

Hello
I deleted the McAfee security software that came with my computer.
I bought & installed Symantec Norton System Works 2004 Pro.
I realized it did not come with a firewall.
So I purchased & installed the Norton Personal Firewall 2004.
I had some really weird problems. Uninstalled both , then reinstalled NSW.
With a little help , everything seems to be working fine , with 2 minor
problems.
#1 I have to disable the email scan feature to send & receive email.
# 2 This machine will not allow me to reinstall the firewall.
Error message MSI must be running during this installation.
Any help as always would be greatly appreciated.
Thanks.
ron

Ronald Murray