Hello Trish, I have been running ME for four years and I would advise that you use a Firewall as well as an anti-virus.
I use Zone Alarm Free firewall and AVG Free edition anti-virus and both work very well to date. Norton can slow ME down considerably.
You should delete all that AdAware finds, I do, and also install SpyBot S&D & SpywareBlaster. Make backups just in case.
You can clean up your system too by using delindex.bat on your Windows ME Start-Disk (bootdiskette).
Keep your hidden C:\_RESTORE Folder down to 500Mb in size.
In relation to the msconfig message, did you check the box "Don't show this message again." if not, then you should do so.
In IE, Tools, IE Options, Advanced, Uncheck:
"Activate install on demand" (Other) , and, "Activate install on demand" (Internet Explorer)