Couldn't access Internet after installing Spywareblaster 4.1

After uninstalling 4.1, I was again able to access Internet thru AOL.
I am reluctant to reinstall Spywareblaster before getting feedback from those who have knowledge in this area.

Microsoft Tech Support ( I run XP Home) says incompatable software applications can occur at any time for multiple reasons.

I previously had problems opening Firefox 2 after two years with no complaints and uninstalled it after seeing many others had varied problems with it.

Prior Spywareblaster editions never caused any difficulty and I would like to be able to reinstall it with confidence that I will not lose Internet connectivity.

Thanks in advance to all who read and respond to this post.