The 64-bit version of Live 8 will not support Max for Live and The Bridge.
You can use the 64-bit version of Live if you are running a 64-bit version of Windows Vista, Windows 7 or Windows 8, or Mac OS 10.5 or higher on an Intel-based Mac.
Information about Live's compatibility with Windows 8.
Live 8.3.1 will be compatible with Mountain Lion.
MIDI hardware doesn't work anymore in Live after upgrading the Mac operating system.
Live uses the Mac's system MIDI functionality. When there're problems with the MIDI drivers, Live will hang while initializing these drivers.
It is unfortunately not possible to use Partner Instruments/Packs with Live Lite 8. Live Intro, Full, or Ableton Suite 8 are required for Partner Instruments.
Unusual high CPU load on older Macbooks with removable Battery
As of Live 8.0.8, Ableton fully supports Windows 7. Please note, however, that your audio and/or MIDI hardware may not yet have Windows 7-compatible drivers.