I have just upgraded MySQL from 4.0 to 4.1 and moved the data onto another disk. It is running on its own without problems. I have also updated to PHP5 and it is also running on my Apache 2.2 server without problems. I cannot get MySQL to work with php5. I have followed all the instructions at php.net, eg updated the PATH, extension_dir and uncommented the mysql extension so it will load. I have checked and the dll is in the path specified. However attempts to connect to MySQL still fail without error. Is there is there an exhaustive checklist somewhere I could check, or could some kind soul walk me through it so I can locate what is going wrong. Any help would be appreciated.