For those interested:
After trying to get PHP working with BadBlue (which didn't work either, dumps a non-informative 'error creating process' page), i decided to try and track down the/a missing dll required by PHP.
The file manager i use (Servant Salamander (www.altap.cz)) has a handy feature that can display lots of useful info about executables and DLLs, including what DLLs they're linked against. So i checked PHP4APACHE.DLL, verifying the existence of all DLLs it depends on, but didn't notice anything out of the ordinary. It depended on PHP4TS.DLL though, so i checked that next. Here, i noticed ODBC32.DLL, which didn't exist on my system.
Searching the forum archives for ODBC32.DLL revealed that other people have had similar problems, and eventually i found a link to http://www.microsoft.com/data/odbc/, where i downloaded Microsoft's Data Access Components, said to contain this ODBC32.DLL among other things.
Bingo, it worked perfectly. Am now happily running PHP as an Apache module.
