1:BUILD_BY[name] student5 1:BUILD_ENVIRONMENT[operating system 32 vs 64] 1:END_BUILD_ENVIRONMENT 1:DEPENDENCIES[list of dependencies with where to get them] LibCrypto++ 5.6 1:END_DEPENDENCIES 1:NOTES[notes on attempted build] Error while trying to compile code in Visual Studio 2008. error C2491: 'Encrypt' : definition of dllimport function not allowed 1:END_NOTES 2:BUILD_BY[name] student3 2:BUILD_ENVIRONMENT[operating system 32 vs 64] Windows 7 64 2:END_BUILD_ENVIRONMENT 2:DEPENDENCIES[list of dependencies with where to get them] LibCrypto++ 5.6 (http://www.cryptopp.com/) 2:END_DEPENDENCIES 2:NOTES[notes on attempted build] error while building in Visual Studio 2013, and after linking the LibCrypto++ files "IntelliSense: a function declared 'dllimport' may not be defined" http://msdn.microsoft.com/en-us/library/62688esh.aspx Based on this website it seems the way they wrote the code is wrong After taking out DLLAPI it gives new errors: Error 17 error LNK2019: unresolved external symbol "public: __thiscall CryptoPP::Algorithm::Algorithm(bool)" (??0Algorithm@CryptoPP@@QAE@_N@Z) referenced in function "public: __thiscall CryptoPP::BlockTransformation::BlockTransformation(void)" (??0BlockTransformation@CryptoPP@@QAE@XZ) C:\Temp\Hourglass\Hourglass.obj Hourglass along with others 2:END_NOTES