Now, I cannot push "enter" to go to a URL in firefox. I have to manually click the button.
I didn't do anything except have my computer update. After update, this happened.
Sorry, just you - Windows 7 is up to date and Firefox is running fine here.
I have not heard of this one before but as always, I suggest to debug this you start by disabling all add ons just incase one of them has disabled this.
Do you use AVG for anti-virus by any chance? This post suggests disabling the AVG extension in Firefox.
It is just a coinsidence I think. You should try Safe Mode of Firefox. An auto-updated extension may lead it.