I upgraded by Vista Home to Vista Ultimate and now my DVD player isn't working. I don't even see when I open my computer icon. I get the following issue
Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)

See Microsoft Knowledgebase Article ID: 314060:
Your CD drive or DVD drive is missing or is not recognized by Windows or other programs
"Your CD drive or DVD drive is missing or not recognized by Windows or other programs, so you cannot play or access a CD or DVD. This issue might have occurred after you installed, uninstalled, or updated a program or Windows Vista."