64 bit applications confusing me

[like2codecpp]

I made a couple of 32 bit programs a while ago but now I want to port them to 64 bits. I managed to write some brutally simple console apps but anything that links with libraries from the Windows SDK gets errors. for example: LIBCMT.lib(crt0dat.obj) : fatal error LNK1112: module machine type 'x64' conflicts with target machine type 'X86' , I dont even know what LIBCMT.lib is and I never even linked with it, I get similar errors with libraries like SDL. Does anybody know whats wrong or how to fix it? I'm using VC++ 2010.