If you run DependencyWalker on lib\auto\DBD\DB2\DB2.dll you'll find out that it relies on .... when apache (not a browser) runs your program, it doesn't know where to find the dll files DB2.dll depends on

Its just a matter of editing %PATH% for apache (or the user it runs as), and whatever DB2 specific env vars (like DB2_HOME)

You'll learn soon enough not to bother looking inside DynaLoader.pm (the error message ought to mention this, but hey :)