Well, I'm now set up with CGI on my XP - IIS 5.1 - PHP 5.2.6 system. And its much more fun now, it doesn't seem to be kicking off all those Access Violations, as isapi did. Many thanks for that. But now where xdebug worked (on those rare occasions without access violations) - nada. NetBeans tries to load xdebug, and tries and tries, and nothing good happens (it doesn't connect). I'm using php_xdebug-2.0.4-5.2.8-nts.dll, corresponding to the download link "5.2 VC6 Non-thread-safe". Looks right to me, but what do I know. (Yup, the ini file points to this replacement for the ts version I used before, and the 4 xdebug parameters are set.) If the dll isn't the problem, there doesn't seem to be much more that could be wrong. So simple, yet I've screwed it up. Any suggestions? It would REALLY be nice to have a debugger. Banging my head against the wall is starting to hurt quite a bit.