Just stick a Delay(1) in your main loop to give Windows some breathing room.
For most games you will want to let the game hog most of the CPU cycles.
For aplication programs use Delay(20) when you don't need to update the CPU intensive parts (rendering, collisions, picking, etc, and Delay(1) when you do. Use a global variable as a flag to control which gets used and whether the CPU intensive routines are run. This should bring your idle time CPU usage down to below 0.5%.
For most games you will want to let the game hog most of the CPU cycles.
For aplication programs use Delay(20) when you don't need to update the CPU intensive parts (rendering, collisions, picking, etc, and Delay(1) when you do. Use a global variable as a flag to control which gets used and whether the CPU intensive routines are run. This should bring your idle time CPU usage down to below 0.5%.