Hi, I need to use the windows performance counters to check the disk length, I tried to use WMI, but it was not compiling in vc++ 6 and I didn't find the compatible SDK in windows7. I also tried the IOCTL_DISK_GET_LENGTH_INFO, but this was also not compiling, it didn't support on windows 7, can you please tell me how can I proceed to compile IOCTL_DISK_GET_LENGTH_INFO in my current setup.