The PCI to PCI Bridge on a PC or Laptop is an onboard or external device that lets either one PCI Bus connect to another PCI Bus, or bridges a PCI bus to another technology allowing inter-connectivity. For example Texas Instruments makes a PCIe to PCI adapter card which does exactly as described, it doesn’t require any additional drivers in Windows.
If this is a device that is appearing in your device management and it is appearing to not be installed there could be a chance that the motherboard device drivers haven’t been installed. Technically if you’re not noticing any issues with your computer you can ignore it.
To fix this issue you will need to install the drivers for the chipset in your device whether that is a Intel, Nvidia, VIA or some other chipset. The best option is to run Windows update as there most likely are drivers that can be updated.
