not sure of windows, but do a search of files for the perl folder, and it usualy looks like #!/(full path to folder/perl
the folder name might vary, but in general there is a way to find it, you gotta do a google search or someone else here give you the windows command to find it!
there will be several folders, like perl, perl5.8.. perl4....
here is where i believ the she-bang points in general, point it to the main folder, as pointing it to your latest install will be useless when you upgrade, and you have to change all your scripts to accomodate!