error accured when installing plz I need help

hi I found a problem when I try to install php from the installer I have windows xp service pack 2 with IIS 5.1 I install all this (extras, extensions and dll files) it gives me a msg that it can't update httpd.inf and you should manually update your system and when I try to open php.exe (after installed) it gives me many msgs with "the application failed to start because OCI.dll was not founld, re-install the application may fix this problem" and gives me this msgs with other dll files plz I need your help if there's not the the correct e-mail to send this problem plz send me the correct mails to send to them