I have a C program that compiles fine in 32 bit but when I try and compile in 64 bit I get the error: error LNK2019: unresolved external symbol __imp_InitCommonControls referenced in function ProgressBar. I've included windows.h and commctrl.h. In the project \properties\VC++ Directories\Include directories, I've tried to add C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Include to the inherited values which is where commstrl.h resides. What am I doing wrong?