I've been using Firefox for over a year and about a week ogo, I did an update for firefox and since then I've not been able to use my Yahoo (where my e-mail adress is) tool bar nor have I been able to use my MaCFEE tool bar. when I go to "Extras/Add-ons" it shows them both sa installed but not as active. Instead, it wants me to either deactivate or uninstaal them. 
I feel very uncomfortable surfing without any site adviser and that is why I tried to download WOT. I hope that this problem can be solved before I decide to leave Firefox and use another Browser.
I would like to request a quick responce/resolution to my problem. Thank you.

I have tried 3 times to download the add-on "WOT" from Modzilla.org to be used on my Firefox. Each time a get a window opening up that states "Firefox konnte das Add-on von folgender adress nicht installieren. https//addons.mozilla.org/firefox/downloads/file/167302/wot_safe_surfing-20120910-fx+sm.xpi?src=hp-dl-featured. Grund; Bei der Installation ist ein unbekannter fehler aufgetreten. Scauen sie in der Fehlerkonsole für weitere Information nach.-203", which I did and didn't find anything about "WOT". I've been using Firefox for over a year and about a week ogo, I did an update for firefox and since then I've not been able to use my Yahoo (where my e-mail adress is) tool bar nor have I been able to use my MaCFEE tool bar. when I go to "Extras/Add-ons" it shows them both sa installed but not as active. Instead, it wants me to either deactivate or uninstaal them. I feel very uncomfortable surfing without any site adviser and that is why I tried to download WOT. I hope that this problem can be solved before I decide to leave Firefox and use another Browser. I would like to request a quick responce/resolution to my problem. Thank you. Frank Fellner