About the result of this program

[Liubbbb]

I try to run the Tester.exe in Windows 7 for x64, but the screenshot results that saved in C:\CopyScreen2.bmp file is a picture with black content. And I find the value of parameter "g_pVideoMemory" is 0 in the memory by Debug! I don't known what going wrong,please reply me when your are free, thanks!