From where will I get the C compiler and how to set up the environment for it ?
If you have Strawberry Perl then you should already have the compiler, and the environment should be set up. If you have ActivePerl, then you simply need to ppm install MinGW.
Cheers, Rob UPDATE: But I think the Win32::TaskScheduler source needs a Microsoft Compiler (even then, it won't build for me with VC7.0) and both of the possibilities mentioned above provide you only with the MinGW compiler.