Change the internet browser

Please, my system is Windows XP SP3 with internet explorer 8 and i have some problems with Zero-K interface.
For example : in Unlock Page, when i fly hover a technologie i see : $unlock$[number] and i don't know this technologie is it.
When I go into "SETTINGS" menu and after into "lobby log history", i can see, in second line : "26/10/2015 18:00:13: Using Internet Explorer 8".
Zero-k lobby cal IE 8 but i want use FireFox because that can resolve my interface's problems. Is it possible to change this into a parameter ?
I'am sorry for my english, i'm french...

Thx for your quick reply ! It's so good ! ;-)

Yes I know, I'm Informatic System Manager.
But I'm waiting the chrismas father... LOL