Better DON'T do that:

http://pcsupport.about.com/od/browsers/f/removeiexp.htm

http://kb.mozillazine.org/Mozilla_Suite_:_FAQs_:_Remove_IE

thank you

Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.

You need to update your Firefox installation, you are 16 updates behind the current 3.6.23 version.

Use Help > Check for Updates.

So... even though there is a better system (Firefox) we are stuck with Bill Gates monopoly and it constent message "Do you want to make Windows Explorer your main..."

nicklap I presume you've read ideato's first link, particularly.

It is always a good idea to have a second up-to-date browser in case you have a problem with your default browser. It doesn't have to be Internet Explorer although uninstalling it fully is not easy because it is so enmeshed with the operating system.

It is easy to install Google Chrome or Opera.

For the record, Windows Explorer is the file system manager/browser; Internet Explorer is the internet browser.

nicklap wrote:

constent message "Do you want to make Windows Explorer your main..."

1. Start Internet Explorer.
2. Depending on the version, click either the Gear icon on the right side of the toolbar or open the Tools menu, then choose Internet Options.
3. In the window that opens, click the Programs tab.
4. Depending on the version, uncheck either the Tell me if Internet Explorer is not the default browser or Internet Explorer should check to see whether it is the default browser option.
5. Click the OK button.

Well done Gingerbread Man, that was exactly what I wanted