Sometimes when a PC has difficulty reading a CD/DVD, Windows will default to a “safe” mode or PIO mode on that particular IDE channel unexpectedly. Symptoms of such a problem are constantly choppy audio and unsatisfactory performance in general. These conditions will be far worse than standard performance.
To check for certain if a system has defaulted to PIO mode, open up the Device Manager and look at the properties of the primary and secondary IDE channels. That is, Device Manager > IDE ATA/ATAPI controllers > Advanced tab. If you see anything that resembles PIO mode instead of Ultra DMA or UDMA mode 0-5, there is a potential performance issue.
The best way to fix this is to completely uninstall the IDE channel in Windows Device Manager. Yep, just right-click on that sucker and uninstall it. Don’t worry, Windows will detect and install the device again automatically upon system restart. Your system should once again go back to UDMA mode and speed up significantly as normal, at least as far as audio/general performance is concerned.