My daughter thinks her onboard video is kaput. Is there a problem installing a PCI card? Is there any way to disable the onboard video so it won’t be detected on boot? Is it necessary to do that?

The MB is in an El Cheapo MyFavoritePC 500 Celeron I got free for opening an E-Trade account. MyFavoritePC is out of business and my daughter doesn’t know how to determine what it has for a MB. I have a hard time talking her into taking the cover off the computer.