in reply to Unable to load Strawberry perl shell on windows 7

CPAN takes out a lock to make sure that it is only running once.

The lock file normally contains a PID of the other CPAN process. It seems that the content of this file has become corrupted and contains null characters. CPAN is then choking when it tries to kill a non-numeric PID.

The simple solution is hopefully to remove the ".lock" file before running CPAN.

Do the following to find the path to CPAN home.

perl -MCPAN::Config -e "print $CPAN::Config->{cpan_home}"
Then look for and remove the file named .lock under that path.