Added CGI from 'Add features and roles Wizard'? ('Server Manager'->'Manage'->'Add roles and features' then 'Server Roles'->'Web Server (IIS)'->'Web Server'->'Application Developemt')
Setup *.pl via 'Add script map' under 'Handler mappings' and set the executable path?
What is the setting 'Impersonate user' under 'CGI' within the website config?