hi all out there, this morning my firefox works fine, but i've been on the net the whole day, and i think im infected with some viruses or what, ok straight to the point, when i open firefox, it shows my normal homepage, but after about 30 seconds it starts to open up new firefox window, and the new window dosent show my homepage (yahoo) but it shows the google search page.. any1 knows what is happening? need help!

if i uninstall and install firefox again, may the problem be solved?

add-ons for what?

i think there is no suspicious add-on installed, i've just check it

how and where is the firefox directory, other than in the program files