apache startup

I am new to this, and I just installed apache with localhost as the
host and directory. anyway, i hit the start button on the monitor and
get "the requested operation has failed." I shut off virus scan, and
checked to see if I needed any updates, im runnin windows xp, but it
still doesnt work. i know my internet provider doesnt allow you to
run servers, so that is why i put localhost instead. the first time i
just let it go throught the default settings, it recognized
everything, and still gave me the error message. please help a
frustrated rookie.