If you are building you DLL on one Windows PC and your program works there, of course you can copy the exe and the DLL to another Windows PC and run it there.
You might get problems if the Windows differs. If you build for an x64 system and the target system is a 32 bit system, your program won't run. Also if you explicitly build for Windows 7 your program might not run on an older Windows. This is especially true for Visual Studio 2013 which by default only generates code for Windows 7 minimum.
So when building the program you might need to set the project/build settings according to your target machine.
When copying the exe and the DLL you need to put them in the same folder. You might also need to add Visual Studio DLLs like the C(++) runtime DLL. You'll find these in the VC\redist
folder in the Visual Studio installation folder.