can't start or install from installer of php4 on apache on windows xp

hey guys
i have problem
i had downloaded and copied php4 files to the c:\php
and downloaded the installer and run it
but the installer says "sorry, the software to automatically configure 
the Apache httpd.conf file has not yet been written. You will have to 
configure Apache manually. Seethe install.txt file for more details."

i tried manually too.
i added the lines that the manual says but its of no use
apache says requested operation failed.

help me guys