'No Audio Device' Error

If you have experienced a Windows "No Audio Device" error, it most likely means that your sound card is not installed properly. Even though other problems can cause this error, an improperly installed sound card is the most common reason. If the audio card isn't properly connected in the motherboard or you do not have an audio controller connected, you will get this error. Also, it is possible that the device you are trying to use is not compatible to the motherboard you are using.
Troubleshooting the most common error
Here are a few steps to take to solve the most common error, an improperly installed card:
You will first need to find your audio controlling device or controller. This controller is what gives you the ability to adjust the sound for everything. From your start menu, go to your control panel. Then, go to add hardware and search for the hardware yourself. Don't let the computer search for it automatically, because if it is improperly installed it may not be seen. Then, scroll down to sound devices and search for your audio controller. Check the properties of the device, and see if it is installed properly. If it isn't installed properly you will see a yellow highlighted question mark beside the device's name
• The best way to solve this problem is to uninstall your sound card and drivers. You will reboot, enter the bios, disable the onboard audio, game port, and midi. Then boot back into windows, go to add remove programs and make sure that any programs for the device was removed.
Next, you should reinstall the sound card and drivers. It is possible driver updates have been made since the sound card was manufactured and released, so it is a good idea to visit the manufacturer's site and see if there are driver updates. Once you do this, restart the computer again. The problem is (more than likely) the default device in audio properties is still the onboard, you can select the creative devices and it will probably work, but it will be better to disable the onboard all together.
Uninstalling and reinstalling the sound card will more than likely fix your problem.
Other troubleshooting tips
If you are still experiencing difficulties, try these other troubleshooting ideas.
• If you think your sound card may be 'dead', before buying a new one, I would recommend borrowing one that is fully functioning from a friend, if possible, and installing that one to see if the error is in the card itself.

• Try using a different PCi slot, that way windows may detect it as new instead of trying to reconfigure it on the slots its currently on. This can also help you to determine whether one of the slots are bad.
• If you have an onboard sound card but are trying to use a sound card you bought separately, ensure the onboard one is disabled.
Always ensure the sound card you purchase is compatible with your board. If it doesn’t say on the packaging, do a little research online prior to the purchase.

Cisco CCNA Certification: Error Detection vs. Error Recovery

Passing the CCNA, Intro, and ICND exam is all about knowing and noticing the details. (Which makes perfect sense, since becoming a master networking administrator or engineer is also about noticing the details!) One such detail knows the difference between error detection and error recovery. While the terms are sometimes used interchangeably, they are not the same thing.

Error detection is just that - error detection only. Two common error detection methods are found at the Data Link layer of the OSI model, the FCS (Frame Check Sequence) and CRC (Cyclical Redundancy Check). A mathematical equation is run against the data in the frame, and the result is sent along with the data. The receiver runs the equation again, but this time. If the result is the same, the frame is considered valid; if the result is different, the frame is considered corrupt and is discarded.

Note that the FCS and CRC do nothing in regards to retransmission. They are strictly error detection schemes.

For an example of error recovery, we look to the Transport layer, where TCP runs. TCP performs reliable delivery, and the reason we call it "reliable" is that TCP uses sequence numbers to detect missing segments. If the sender determines from the sequence numbers that the remote host did not receive transmitted segments, the sender will retransmit the missing segments.

The key to keeping the terms straight in your head is to remember that while both error detection and error recovery both detect problems, only error recovery does anything about it. It's also worth reading an exam question twice when you see either term!