Off CPAN? Bad. Judging by your error messages, the module isn't properly installed, you seem to be missing the DLL. You best install a precompiled binary distribution. It's the only way to make it work if you don't have the proper C compiler; for ActivePerl (and compatibles) that's MS Visual C.

Like Roger said, for Activeperl, PPM is the way to go. If you don't have direct internet access, you can download the latest precompiled versions here:

• Win32::API 0.41 for Activeperl 5.6.x
• Win32::API 0.41 for Activeperl 5.8.0

Both archives contain all the files you need to install this module, complete with DLL, without any internet connection. Just decompress the .zip file, preserving the folder structure, and run PPM from the directory you decompressed it into — you don't need to decompress the .tar.gz file, PPM does it by itself. You may use this command line at the DOS prompt:

PPM install Win32::API
[download]

You may delete the decompressed files again after installation.