Here are 4 easy steps that allows you to optimize Windows Vista and for better audio performance. (these will also apply to Windows XP users)
1. Changing Processor Scheduling to 'Background Services':
Go to System > Advanced system settings > Performance settings > Choose to adjust for best performance of 'Background Services' in the Processor scheduling.
2. Adjusting visual effects to 'Best performance':
Go to System > Advanced system settings > Visual Effects > Choose 'Adjust for best performance'.
3. Disabling system sounds:
Go to Sounds > Click the 'Sounds' tab > Change the sound scheme to 'No Sounds'.
4. Optimize the Power Management on your PC
Go to Power Options > Choose the 'High Performance' power plan.