You're getting the unixy paths because you're using a perl compiled on (or targeted at) cygwin - which is a layer on top of windows that maps a (pseudo) unix-style folder structure on top of Windows's folder structure.

If you'd be using, for example, the on Windows commonly used ActiveState perl, you'd get the same complaint about @INC, except it'll spit out a list of paths as you're expecting: something like "C:\Perl\lib" and "C:\Perl\site\lib".

Because you're using a cygwin perl you CAN'T (afaik) use PPM, so go with the link provided by shigetsu.