Problem with IE and Firefox

I installed Thunderbird yesterday and when I open IE, with FF closed, and type in a URL to visit in IE, the URL is opened in FF!!!
How do I prevent that without making IE the default browser? Before I installed Thunderbird, I never had this problem. Anyone know what is going on??

 

Thunderbird should have nothing to do with it.
If you type a URL in IE, it should open in IE. However, if you click on a link Thunderbird, and Firefox is your default, Firefox will open.
TB and FF are my defaults, but this does not preclude me from opening pages in IE.

 

That's the way it used to be, but no more. A URL in IE now opens in FF.

 

Somehow under "Set Program Access and Defaults" IE had been selected to have no access! I monkeyed around with this and now everything seems to be OK again, but I had to make IE the default browser. I wonder if MS is somehow playing games with my machine?

 

Bob,

Sometimes, making IE the default browser, then disabling the setting and making Firefox the default browser will allow links clicked in IE to be opened in IE.

 

Thanks, I'll try that.

 

Are you using Custom settings? I allow everything, except for Windows Messenger. I never had to make IE default since I, first, got WinXP