If you install a PCI-express video adapter other than a PCI-e x1 in a 8098, 8171, 8172, or 8173 system, you may receive a 4-2-3-3 post beep error.

Any of the following systems configured with a PCI-e video adapter that is not PCI-e x1:

• ThinkCentre S51 (type 8098, 8171, 8172, 8173)
  

Do not replace any hardware. The system only supports PCI-e x1. While the system riser card does have a standard PCI-express bracket that normally would support x1, x4, x8, and x16, these systems ship from manufacturing with a plastic bezel that covers everything except where a PCI-e x1 card would populate. The bezel is removable therefore it is possible for a user to insert a non-PCI-e x1 card and thus receive post error 4-2-3-3.