怪啦！今天的Apache和IIS都沒法正確加載php_mysql.dll。google了一下，原來發現出現這個問題的人還不少，PHP startup: Unable to load dynamic library :E;\PHP5\ext\php_mysql.dll。明明php_mysql.dll就擺在extension_dir (= "E:/PHP5/ext")下的嘛，怎么會呢？而且就在php_mysql.dll之前的extension=php_gd2.dll都沒有出現這個問題，怪了！有人說copy libmysql.dll到 ％windir％\system32下就可以解決問題，其實"華山不這一條道"：

PHP被我挪了個窩，%ProgramFiles%到E:\下，導致一些要依賴于其他dll才能工作的擴展無法正常加載這些dll，出現加載擴展出
錯，以剛才的php_mysql.dll為例，php_mysql依賴libmysql.dll，由于給PHP5挪窩了，而又沒有把新的E:\PHP5夾道%PATH%中去
，所以沒法找到這個libmysql.dll，才會出錯。所以為了能夠使用這些mysql的擴展，除了要正確地配置extension_dir外
，還得保證系統能夠這些擴展所依賴的dll，解決的辦法有兩個：
1 將這些依賴的dll拷貝到％windir％\system32下
2 或者將PHP5的安裝目錄添加到%PATH%中。
無論那個都可以很好地達到我們地目的。
夠簡單的，但是有時候還就想不到哪兒去。
到底哪些擴展依賴哪些dll呢？以下列表可以幫助我們回答這個問題：
php_curl.dll CURL, Client URL library functions Requires:   libeay32.dll, ssleay32.dll (bundled)
php_domxml.dll DOM XML functions PHP = 4.2.0 requires: libxml2.dll
   (bundled) PHP >= 4.3.0 requires: iconv.dll (bundled)
php_fdf.dll FDF: Forms Data Format functions. Requires: fdftk.dll
gnu_gettext.dll (bundled), PHP >= 4.2.3 requires libintl-1.dll,
php_iconv.dll ICONV characterset conversion Requires: iconv-1.3.dll
php_ingres.dll Ingres II functions Requires: Ingres II libraries
php_interbase.dll InterBase functions Requires: gds32.dll (bundled)
php_java.dll Java functions PHP = 4.0.6 requires: jvm.dll (bundled)
php_ldap.dll LDAP functions PHP = 4.2.0 requires libsasl.dll(bundled),
     PHP >= 4.3.0 requires libeay32.dll,ssleay32.dll (bundled)
php_mcrypt.dll Mcrypt Encryption functions Requires: libmcrypt.dll
php_mhash.dll Mhash functions PHP >= 4.3.0 requires: libmhash.dll   (bundled)
php_mcrypt.dll Mcrypt Encryption functions Requires: libmcrypt.dll
php_mhash.dll Mhash functions PHP >= 4.3.0 requires: libmhash.dll   (bundled)
php_msql.dll mSQL functions Requires: msql.dll (bundled)
php_mssql.dll MSSQL functions Requires: ntwdblib.dll (bundled)
php_mysql.dll MySQL functions PHP >= 5.0.0, requires libmysql.dll   (bundled)
php_mysqli.dll MySQLi functions PHP >= 5.0.0, requires libmysqli.dll   (bundled)
php_oci8.dll Oracle 8 functions Requires: Oracle 8.1+ client libraries
php_openssl.dll OpenSSL functions Requires: libeay32.dll (bundled)
php_oracle.dll Oracle functions Requires: Oracle 7 client libraries
php_sybase_ct.dll Sybase functions Requires: Sybase client libraries
php_xmlrpc.dll XML-RPC functions PHP >= 4.2.1 requires: iconv.dll   (bundled)
php_xslt.dll XSLT functions PHP = 4.2.0 requires sablot.dll,  expat.dll (bundled).
        PHP >= 4.2.1 requires sablot.dll, expat.dll,  iconv.dll (bundled).

看文檔耐心不夠，自己找了點麻煩。：P