External speakers no longer working

Question

We have a Windows Vista laptop. On Monday we hooked it up to external speakers, as we always do, and they worked fine. On Tuesday, we did the same but then the speakers did not work. Weirdly, the laptop internal speaker does work. Nothing was changed between Monday and Tuesday. What happened and, more importantly, how can it be fixed?

BTW we tested with other speakers (and cable) and that didn't help. So it seems like a laptop issue.

If I unplug my speakers during playback, the laptop speakers always work!

Also, I've tried the obvious.

Update: We've found out that it also affects sound via USB! So it is definitely not a hardware issue!

Update 2: After the comments below, I tried reinstalling the drivers. This has not helped.

Solved: Details below in my answer. Bounty therefore instead given to vcsjones whose answer tells us how to prevent this happening. (This is an ASUS laptop with Realtek sound driver.)

Answer 1

As mentioned in the updated question, this is an ASUS laptop using Realtek driver. It appears that Windows Vista updated / changed the driver by itself.

I tried to delete the device driver and then reboot, but it looks like Vista selected a default invalid driver. Eventually I installed a driver from the ASUS site on advice of the ASUS helpdesk. This worked.

To prevent this happening again, please see vcsjones' answer, on this page.

Answer 2

To stop it, I think what you can do is

1. right click "Computer", go to "Properties",
2. Click "Advanced System Settings" - if a UAC dialog appears, click "Continue"
3. On the "Hardware" tab click "Windows Update Driver Settings"
4. Check, "Never check for drivers when I connect a device".
5. Click "OK".

Answer 3

Try short way first. If short way does not work then the long way should. Some of these tips are for Win7 but should be close if not same.

Short Way:

Control Panel-System-Advanced System Settings-Hardware Tab-Device Installation Settings-Select "No" let me choose what to do, Then Never Install Driver from Windows Update. then click Save Changes.

Long Way:

1.)  Go to Start–>Search type in gpedit.msc
2.)  Click the file to open the Local Group Policy Editor
3.)  You want to go here: Computer Configuration->Administrative Templates->System->Device Installation. Click on the subfolder Device Installation on the left and on the right side you will see the possible restrictions.
4.)  Right Click on Prevent Installation of Devices not described by other policy settings and edit this option, set it on ENABLED.
5.)  Reboot Windows and it shouldnt have ability to load your system with its standard driver, open gpedit.msc again and revert the change so you will be able to install your driver.

Answer 4

Since the second set of speakers also don't work, and the laptop is routing sound to the onboard speaker even when something is plugged into the port, I think the port itself has failed.

If that's the case, it would need to be replaced. Depending on your hardware that can be done by a shop or the manufacturer.

Answer 5

there is a "short" on your port - if no external speakers work and the built in speakers dont work when external speakers are plugged in , then you most likely have a short on that port . You will need to have the port fixed or do it yourself if you have that skill set (soldering, etc...) - do headphones work? most often the headphone and external audio port are on the same board - if its a hardware board issue then headphones would exhibit the same behavior - if not then you still just may have a bad port -