How to get Dell Optiplex 755 speakers to work on Windows 7
After upgrading a Dell Optiplex 755s to Windows 7, you might have noticed that your audio stopped working, and perhaps you see a red “X” over your audio adapter in Device Manager. Dell has identified the Opiplex 755 as having “basic functionality” with Windows 7, meaning that Dell hasn’t released a set of Windows 7-specific drivers for the different components, including audio. You must use a combination of built-in Windows 7 drivers and Windows Vista drivers to get all the components working as well as possible.
Use Windows Update to Find a Compatible Driver
Click Start, type “Windows Update” in the Search box (without quotes here and throughout) and select “Windows Update” when it appears in the search results.
Click the “Check for updates” link and click “Optional updates are available” when the process completes. If the “Optional” link doesn’t appear, there are no driver updates from Microsoft available for your computer and you can skip this section.
Check the box next to an audio driver update if one exists. Otherwise, skip to the next section.
Click “OK” and “Install Updates.” You’ll probably need to reboot your computer afterward, and the speaker should work at that time.
Install a Windows Vista Audio Driver
Browse to Dell’s Drivers and Downloads page for the Optiplex 755.
Choose either the 32 or 64-bit version of Windows Vista from the Operating System drop-down menu. You need to choose the correct architecture for your operating system. If you’re not sure whether your computer is a 32-bit or 64-bit system, you can find out by clicking Start, right-clicking “Computer” and selecting “Properties.”
Expand “Audio” and click “Download File” next to the most recent driver version.
Choose “Single file download” and click “Continue” to download the file.
Launch the downloaded EXE file. The program will prompt you for a directory to extract the driver files. By default, the files will extract into a subdirectory in C:\Dell\Drivers, although you can designate an alternate location if you want. Close the dialog box after extracting the files.
Click Start, type “Device Manager” in the Search box and click “Device Manager” when it appears in the search results.
Expand “Sound, video and game controllers” and double-click the integrated audio option, which will probably have a red “X” through it.
Click the “Driver” tab and the “Update driver” button.
Click “Browse my computer for driver software” and click “Browse.”
Navigate to the folder where you unzipped the Dell audio driver files earlier and click “OK.”
Click “Next” and follow the on-screen instructions to install the audio driver.