PGP in Windows 7

Question

I have 2 windows applications for pgp decryption. Both are on windows 7. One is prototype and another one is .net customized application. All I want to do is to reuse the source code of prototype in my customized application.

When I execute the prototype, decryption is processed successfully. But for the customized one, the exactly source code doesn't work.

My environment summaries are as follows.

OS : Windows 7
Visual Studio : 2005
.net version : 2.0
pgp : 1.2.5

Thanks in advance.