What is CIR Registry?
CIR Registry is a software program developed by ITE, is considered a driver that is commonly found on Dell systems. Other technical notes report this as part of the PC DT/NB product and is a single-function PCI Express to PCI bridge, which is compliant with the PCI Express Base. This driver supports PCI-to-PCI bridge with subtractive decode for legacy devices.
Many of the new Dell professional displays don't have the audio feature but when connected to a computer using the HDMI cable the computer will attempt to default the audio playback through the HDMI connection anyway. This is why you may not have audio on your computer, even if you have built-in audio on your laptop or desktop computer.
To resolve this issue you will need to change your default audio device to one that does have audio functionality. Here are some steps that might help.