Hah. I put NetNanny on my sister's computer but thats all...who cares if she uses firefox or IE(not that she knows wat these 2 are lol). But i did made sure all the crap is blocked...although i am probably wrong...teenagers are into "bad" stuff at this age(she's 15) but i mean...MY SISTER...watchin ...

but i just dont understand whats wrong with using firefox....especially that you are brothers...you should understand each other lol....anyway just put a BIOS pwd on it (its when you press F8 or w/e yours is when your computer is loading to enter setup.

Another idea is to set up 2 accounts on winXP...one has firefox on the desktop and uses that as a default browser and the other has ie as default..simple enough.