Create Language plperl - Error: could not load library plperl.dll
Because I missed 3 files dll (MSVCR90.DLL, PERL514.DLL, IESHIMS.DLL) in Windows I could not install the language pl/Perl.

Here my steps to solve:


Using  "Dependency Walker" tool to check dll files missing (if any). After installing, you open plperl.dll file and find errors.
Install dll files missing.
Install ActivePerl (to install Perl on window, It will automatically set Perl bin folder to windows environment variable)
Restart postgresql service 
Test: 

    createlang -U postgres plperl postgre  (it's ok)
    CREATE or replace LANGUAGE plperl      (it's ok)



Download (I just can post 2 links)


Dependency Walker tool: http://www.dependencywalker.com/ 


Reference: http://www.mkyong.com/database/install-perl-in-postgresql-the-specified-module-could-not-be-found/