betb,
Normally, if you install Avast 4 over Avast 32, no problems are encountered.
Should you encounter any trouble during the install.....uninstall using the Add/Remove feature in Control Panel, and start over.
I am not aware of any broken links in the pulldowns.....
Could you give me the links for the ones that are not working for you?
This way, I can check them or turn the bug report in to the Avast Team.
Good luck