3.将C:\PHP\php.ini-dist这个文件改名为PHP.ini,复制到“C:\WinNT（Winodws98系统为C:\Windows）”目录下，并修改里面的内容，具体如下：
找到“extension_dir = ”改为“extension_dir=c:/php/extensions”
再稍微往下看，改成这个样子：
;Windows Extensions
;Note that MySQL and ODBC support is now built in, so no dll is needed for it.
;
extension=php_bz2.dll
extension=php_ctype.dll
extension=php_cpdf.dll
extension=php_curl.dll
extension=php_cybercash.dll
extension=php_db.dll
extension=php_dba.dll
extension=php_dbase.dll
extension=php_domxml.dll
extension=php_dotnet.dll
extension=php_exif.dll
extension=php_fdf.dll
extension=php_filepro.dll
extension=php_gd.dll
extension=php_gettext.dll
;extension=php_ifx.dll
extension=php_iisfunc.dll
extension=php_imap.dll
extension=php_interbase.dll
extension=php_java.dll
extension=php_ldap.dll
extension=php_mhash.dll
;extension=php_mssql65.dll
extension=php_mssql70.dll
;extension=php_oci8.dll
extension=php_openssl.dll
;extension=php_oracle.dll
extension=php_pdf.dll
extension=php_pgsql.dll
extension=php_printer.dll
extension=php_sablot.dll
;extension=php_snmp.dll
;extension=php_sybase_ct.dll
extension=php_yaz.dll
extension=php_zlib.dll