You can update your CD/DVD-ROM device driver in several ways. Since you just reinstalled Windows XP, try using Windows Update first because you need to update the operating system regardless. If that doesn’t do the trick, move on to the next tips.
Using Windows Update to Update Acer Drivers
After restoring a computer and reinstalling the operating system, it’s important to completely update it. Windows XP SP3 contains many updates, but not all. For example, any update released since XP SP3 will also need to be installed on your system. Go ahead and do that now. Not only does Windows Update patch your operating system with the latest fixes, it also contains a variety of updated Windows drivers for hardware. Reboot the PC once the updates have been installed and see if your CD/DVD-ROM driver is still an issue.
Downloading Acer Aspire Drivers from Acer
In most cases, the manufacturer’s Web site is one of the best places for finding updated device drivers for specific models. In this case however, the Acer Web site didn’t list any specific device drivers for the Acer Aspire 5100 series CD/DVD-ROM. You might double-check Acer.com by entering your specific country and clicking on the Driver and Download link. There may be slight differences between models by country, so it’s possible that a driver is available if you’re in a country other than the United States.
Using Device Manager to Update Acer Drivers
The Device Manager is a tool built into the Windows operating system for situation such as this. Go to the Control Panel, click on System> Hardware> Device Manager and then double click on DVD/CD-ROM Drives. Your CD/DVD-ROM drive should appear in the list. It will most likely have a yellow warning icon next to it. Right-click it and choose Properties. Click the Driver tab and click Update Driver. Now, choose the Automatic option and let the tool search for updated drivers. If any are found, follow the prompts and reboot the PC.
Removing the Drive from Device Manager
Another Device Manager technique that often forces Windows to search for the appropriate drivers is to uninstall the device and reboot. Once uninstalled, Windows will detect the drive upon boot up and launch the New Hardware Found wizard. If the drive is plug and play, Windows will load the proper drivers for it automatically. Right-click the drive in Device Manager and choose Uninstall.

I’m guessing that this is a built-in webcam on your computer. Did you update your operating system, particularly with Vista? There are a lot of instances with this happening when updating Vista. You probably need to update the drivers and there are a few ways to do this.
Troubleshooting Driver Download Errors
Typically, sound cards and drivers are included with computers. Check to see if you have any. If you don’t or want to upgrade what you do have, you’ll have to purchase a sound card or check for updates on your existing sound card. The following information should help you with what you need to know.