The problem seems to be in the key hook, its seem windows only lets 6 key hooks per app, it maybe a security thing ?.

Just use CreateFile with the CREATE_NEW flag set. You get and error indicating if the file already exists. Then just increment your number and try again.

f0dder, I use F9, the hook is a background hook so the program need no focus.

It works normal until and takes screenshots on pressing the F9 key, but once you have pressd the key 6 times, it does not take any more shots until you close the screen shot app and re-open it.

When you say other win7 work OK, thats maybe because they use the .net.

#include <windows.h>
#include <stdio.h>

void TakeScreenShot(LPCSTR);

int main(int argc, char **argv)
{
   TakeScreenShot("ScreenShot.bmp");
   return 0;
}

void TakeScreenShot(LPCSTR lpszFileName)
{
   keybd_event(VK_SNAPSHOT, 0x45, KEYEVENTF_EXTENDEDKEY, 0);
   keybd_event(VK_SNAPSHOT, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
   
   OpenClipboard(NULL);
   HBITMAP h = (HBITMAP)GetClipboardData(CF_BITMAP);
   CloseClipboard();

   BITMAPINFO bmpInfo;
   ZeroMemory(&bmpInfo, sizeof(BITMAPINFO));
   bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);

   HDC hdc = GetDC(NULL);
   GetDIBits(hdc, h, 0, 0, NULL, &bmpInfo, DIB_RGB_COLORS);

   if(bmpInfo.bmiHeader.biSizeImage <= 0)
   {
      bmpInfo.bmiHeader.biSizeImage =
         bmpInfo.bmiHeader.biWidth *
         abs(bmpInfo.bmiHeader.biHeight) *
         (bmpInfo.bmiHeader.biBitCount + 7) / 8;
   }

   LPVOID pBuf = malloc(bmpInfo.bmiHeader.biSizeImage);

   bmpInfo.bmiHeader.biCompression = BI_RGB;
   GetDIBits(hdc, h, 0, bmpInfo.bmiHeader.biHeight, pBuf, &bmpInfo, DIB_RGB_COLORS);

   BITMAPFILEHEADER bmpFileHeader;
   bmpFileHeader.bfReserved1 = 0;
   bmpFileHeader.bfReserved2 = 0;
   bmpFileHeader.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + bmpInfo.bmiHeader.biSizeImage;
   bmpFileHeader.bfType = 0x4D42; // BM (little endian = MB)
   bmpFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

   FILE* fp = fopen(lpszFileName, "wb");
   fwrite(&bmpFileHeader, sizeof(BITMAPFILEHEADER), 1, fp);
   fwrite(&bmpInfo.bmiHeader, sizeof(BITMAPINFOHEADER), 1, fp);
   fwrite(pBuf, bmpInfo.bmiHeader.biSizeImage, 1, fp);

   ReleaseDC(NULL, hdc);
   free(pBuf);
   fclose(fp);
}