I upgraded my computer to Windows XP but there is question mark on sound

Download & install the appropriate software drive for your sound card. Windows XP provides no support for some older items that Windows 2000 & previous versions provided. Go to the website of the sound card manufacturer or maybe the website of your PC manufacturer if the device came with the PC. They might provide a compatible software driver that can be downloaded & installed on your PC. The ultimate answer is to replace the hardware with something that is compatible with Windows XP. OUCH!

Update your driver! You should be able to right-click on your device and go-to properties. There there should be an option to update , uninstall, details and rollback driver. You want to update.

If none is found, try finding it yourslef like bones252100 said go to the manufacturers website or just Google it.

Good Luck