3) Remove any unnecessary background applications and services you may have installed. This includes any codec packs.
You will need to chase this down systematically. If the system was working fine initially and now doesn't, you need to retrace what you have instralled since that could be interfering. Check task manager at the time you get the delays and see if anything is hogging the system. Check Event Viewer also. If you cannot find anything, this it might be wise to resinstall the OS and start again. Or, if you've got a spare HDD, install a fresh OS on it. Just keep software to a bare minimum and see if the audio still has issue.