Looking for some [freeware/opensource] tool in order to make it easy to profile a big php project on win32 platform. Need to find out which part of code is most time consuming.
You'll want to install and configure Xdebug. It's sort of the de-facto standard PHP debugging and profiling tool.
WinCacheGrind can crunch the profiling output. It's a bit buggy, but it does the job.