I did this with the help of Ableton technical support, and found that my processor state values were set at 5%. Sometimes the minimum and maximum processor state on a machine are set lower than its full potential, perhaps to conserve power or something like that. The second thing is to adjust your processor state. If not though, you can install one for free. If you have the option for an ASIO driver already, then you don't need to install an ASIO4ALL driver. Check to see if the Driver Type is an ASIO one or perhaps it's an MME/Direct X one. To check go to the Options menu, select preferences, then select the Audio tab. You may already be using an ASIO driver though. I grabbed one and it improved my crackling and popping. Two things may remedy your crack and pop issue in my opinion.
