Live does not support using multiple audio interfaces, but some workarounds are possible.
General guide for optimizing Windows for audio.
Live crashes with kernel panic errors
If your audio stream is interrupted, distorting, drop outs and crackles verify, please find here some hints in order to get audio back to normal.
This article holds various steps and settings to reduce the CPU load of Live in case you are experiencing CPU spikes.
The Indexer Process keeps in sync the Live browser with your computer. Under rare circumstances, this process might stop working correctly: find out here how to restore it.
A corruption of the Live database prevents the content to be shown in the Live browser. Find out how to fix the problem here.
You can find your Serato mixes in your Serato Scratch Live Recordings folder.
Error message: "The 64-bit version of Ableton Live cannot run on this computer because the processor does not support certain required features
Live 64-bit won't run on certain unsupported old 64-bit CPUs
Questions and answers regarding the 64-bit version of Ableton Live.