update
if u were using unix, then compiling is okay with the --with-oci8[=DIR]
BUT on windows its easy, use the php_oci8.dll file to be found under C:\PHP\extensions (if u installed the entire php in c:\php)
u may need to copy the dll to your windows directory. check the php.ini file (in windows dir) for the "extension_dir = ./" syntax and place the proper directory at ./
note on win2000 windows directory is c:\WINNT
cheers
nilesh.