The error about "no suitable installation target found" generally means that the ppm utility found a ppm package, but it doesn't correspond to your version of perl (Perl-5.6 and Perl-5.8 aren't binary compatible, which is important especially for packages like Crypt-DES that have an XS component that needs compiling). For example, the packages on the perlpack.webpub.net site have, in the ppd file, an architecture of MSWin32-x86-multi-thread, which corresponds to perl-5.6 (ActivePerl 6xx builds). Since you're using an ActivePerl 8xx build (perl-5.8), this doesn't match the associated architecture of MSWin32-x86-multi-thread-5.8.

ActiveState removed many of their Crypt* ppm packages due to legal concerns. As noted elsewhere in this thread, some such packages are available in the uwinnipeg ActivePerl 8xx repository, including Crypt-DES.

Having said that, if you have VC++, it would be worthwhile to set it up so that you can compile your own packages. However, if you're using ActivePerl, you should be using VC++ 6 (which is what ActivePerl is compiled with); if your version of VC++ isn't 6, you should probably compile Perl on your own and use that. The README.win32 file in the Perl sources discusses how to do this.