Try forcing it
ppm install LWP --force
I don't use ppm often so I'm not sure if that command is correct.
nmake gave errors where it said it couldn't find Program Files - I replaced all "Program Files" mention in the makefile with Progra~1
You can install perl into "program files", but you have to police your path/config, see Changing Perl Config settings, example
C:\>echo echo %~s1 >shortpath.bat
C:\>call shortpath.bat "C:\Program Files\Perl\bin\perl.exe"
For future reference, its better if you copy/paste error messages .