I'll take the issues one at a time:
1.About Firefox: I've been using Firefox since it was released in final form- going on 5 years. Most thing have gone well with it. I have v3.0.17 not. I did the v3.5.5 update and got a compatibility notice for one of my add-ons. It is one I cannot afford to lose. but in spite of stopping before the new install completed, it removed the add-on and all the contents.
2. I spent two days trying to figure out how to recover this and ended up d/l and installing the 'old' version, at that time v3.0.16. It installed right over the later version and I didn't lose anything. I guess what I'm trying to say is that, even with Firefox, new isn't always better!
So I offer you the choice of going back to an earlier version to see if that will resolve the problem.
3. As for the antivirus program: there is a deep divide between some of us: Some say throw away what you now have and install the program of their choice, usually Avira or Avast. This use to be done if it was AVG, but some included
any other AV.
I do not. If you currently have a functioning AV program- whether paid or free-I do not have you change it at the beginning of cleaning. I will instead suggest a more through AV program at the end that you might want to consider. I do not believe in putting something new on an already unstable system.
4. About Toolbars: If you do a right click in the Toolbar section, you will see a list of the Toolbar and those being used are checked. You can remove the check if you don't want the Toolbar. In fact, some program have Toolbars or Searchbars already pre checked on the download site and many don't catch it. AVG might be routing you to the AskBar which is not desirable.
Here's a shortcut that should help from Microsoft:
Toolbar Removal for Windows XP
1. Start> Run> cmd> Type appwiz.cpl > ENTER.
2. In the Currently installed programs list, click Web or search tool bar to remove, and then click Remove.
3. Follow the on-screen instructions to uninstall and complete the toolbar removal.
:
The thing is that most of the Toolbars are 'built in' to a program. In Firefox, you might see the Toolbar listed as an add-on: Open Tools> Add-ons> if it's there, you should be able to disable or uninstall it.
Whew! That was pretty wordy! Did I cover it all?