after having downloaded a new title – whether paid or free – no aftermarket software would run properly
Not true. The software just downloaded would not run properly, but all other aftermarket software previously installed was unaffected.
And yes, there's probably a better method than what I've brought up, but it does work.
Yes, there is a better way. Use Google Custom Search Engine to create your own search engine then once created go to the control panel for that search engine and exclude all the sites you want (you can even use URL pattern matching). You can then add the custom search form to igoogle, google toolbar, firefox search box, or any web page.
New York... when civilization falls apart, remember, we were way ahead of you. - David Letterman