Troubleshooting Random Poor Sound quality from computer
Sometimes sound won’t play properly for the simple reason that your CPU is too slow to handle it! You should first try optimising your system performance a little: go to the Control Panel and open the System dialog. Under the Advanced tab, click on the Settings button under Performance. Under the Advanced tab here, adjust for best performance of Background Applications. This can cause quite an improvement in sound performance. You should also close all unnecessary programs that may hog memory. If you’re still insistent on running many programs at the same time, including sound applications, upgrade!