I had similar issues (on XP version up to SP1) when I installed Perl into a directory whose name contained spaces (i.e. c:\program files\whatever), a practice *not* recommended in release notes. Despite the installation going (apparently) properly to its end, ppm was not working at all, with symptoms like yours.

Two remedies, out of this:

1. install to c:\perl\ (or any other name of your choice, but *not* including spaces)

2. use an old-inherited DOS-trick of defining extended directory names in 8.3 notation (via the tilde, so that "c:\program files\whatever" becomes "c:\progra~1\whatever")