There is no output devices on my toshiba u300, suddenly it stopped and there is no sound, how can i reistall output devices?

Try re-installing the audio driver on your Toshiba laptop.
You can download the audio and device drivers for your model laptop from the Toshiba WEB site from their download page. Make sure you enter the model of your laptop so you can get the correct drivers. Please click on this link: - http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/home.jsp

Try reinstalling the audio driver.
You can download theaudio and device drivers for your model laptop from the Toshiba WEB site from theirdownload page. Make sure you enter the model of your laptop so you can get thecorrect drivers. Please click on this link: - http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/home.jsp http://blitware.com/adpages/driverfetch/manufacturer/?manufacturer=Toshiba&gclid=CMOVxNCBx6ACFSgnawodoHNGbA

You should go to the Microsoft website and search for Windows 7 updates. MS releases updates regularly, so it's a good idea to check there frequently. You can also set your laptop to accept automatic updates from MS.

REINSTALL SOUND DRIVERS . DRIVERS U CAN GET FROM TOSHIBA OFFICIAL WEBSITE

May be there was a virus in your sound drivers files, so norton automaticly removed it, try reinstalling your sound card drivers, also be sure to check their compatibitlity with your windows edition.

Hello....
No Sound, No Volume Control, Mixer not Found, No Sound device installed…etc etc, This is a generic issue with all Windows OS updates....many of the users are facing this issue....this issue began after an auto update from MS changed many IRQs of Win OS, mainly the Sound and Audio Control system of Windows.
1 - R U facing NO Audio / No Sound issue...?
2 - Is ur Volume Control not responding ?
3 - Is ur Sound and Audio Device in Control Panel Grayed out ?
4 - Do u get a msg "No Active Mixer Devices Installed....when u try to open Volume Ctrl etc etc ?

If ur ans to any one of them is Yes...then u are being spammed by Microsoft....as ur Sound Control IRQ is being frozen by a recent update from Microsoft....
NOTE..THIS…IS…VERY..IMPORTANT...
No file update or any sound driver update can fix it, neither Microsoft is issuing any patch to fix it…or giving any help on this.
Full solution is available in my website (Support page)...it's quite simple process to fix it, and I am not charging any money, just doing FREE service to help everyone affected by this stupidity from Microsoft.
www.sureshayyar.110mb.com
visit my Support Page.
many of us are victim of this “stupid” update, my office has 24 PC/Notebooks and almost all of them got this issue one by one in 4 months time period, I head the tech dept here.
all the best...

Check device manager (right click on my computer, select properties, click the hardware tab and then the device manager button). If the sound card is not listed or has a ? or ! on it, go to toshiba's web site and download the drivers to install.

Hope this helps

http://cdgenp01.csd.toshiba.com/content/support/downloads/driver_audio_realtek_os2008015a.exe

download and install this driver...

Hello
The windows Xp installation doesent find your hardrive because you have a sata drive. you need to adjust the settings in the bios so the sata drive appears as a ordinary IDE drive(ide native) or something like that. search in the bios settings.
A other way is to burn a new winxp cd with the Toshiba Satellite U300, sata drivers.
download the http://www.softpedia.com/get/System/Back-Up-and-Recovery/Barts-PE-Builder.shtml
and download the toshiba harddrive drivers and creat a new cd.
but the simples way is to make the change in bios.
good luck

does your sound system work before

what windows you are using xp or vista ??