C:\Strawberry\codes>ppm install http://www.sisyphusion.tk/ppm/Class-Inspector.ppd
Downloading Class-Inspector-1.28...done
Unpacking Class-Inspector-1.28...done
Generating HTML for Class-Inspector-1.28...done
Updating files in site area...failed
ppm install failed: File conflict for 'C:/Perl/site/bin/lib530pthread-1.dll'.
    The package PPM-Sisyphusion has already installed a file that package Class-Inspector
    wants to install. Uninstall PPM-Sisyphusion, or use --force to allow files
    to be overwritten.