Issue Details

My computer will not boot when I put a PCIe card into an x16 slot.
My computer will not POST (Power on self test) when I put a PCIe card into an x16 slot.
 

Solution

First, here are a few troubleshooting steps to determine if the problem is with the PCIe card or the PC. 

• Re-seat the PCIe card in the PCIe slot
• Try the PCIe card in another PCIe slot in the same computer
• Try the card in another computer
• Try a known working PCIe card in the PCIe slot that is having the problems

If the problem lies with the PC, there are a couple of possible steps that could help fix this issue.

• Update the firmware/BIOS for the computer motherboard. (This updated BIOS typically has to come from the motherboards manufacturer)
• Change BIOS settings for PCIe card from AUTO to GEN1 (Options typically are  AUTO/GEN1/GEN2/GEN3)

Additional Information

Note: Intel Skylake chipsets (HD110/Q170) have been problematic. They did not work with 1433 and 6323 PCIe cards that were known to work. 
Note: The PCIe-1433 has been seen to prohibit a Dell OptiPlex 3040 from booting as well.
Note: For HP computers you can disable the PCIe Security setting on the BIOS following this procedure: External Link: HP Desktop PCs - Computer Does not Start After Installing a Video Card (Windows 10, 8)
Note: There is an issue with the Dell Precision 5820 PCIe resource allocation and NI PCIe hardware. Workaround: you may be able to use the 5820 with an NI MXI system after installing the MXI BIOS Compatibility software and flipping DIP Switch 1 on the PCIe card to ON or trying different PCIe slots can be helpful as well.
 
The 5820 also gives the user some prebuilt PCIe configurations for how the 256 lanes are assigned to the multiple PCIe slots. See Table 3 of: PCIe Bus Allocation in Dell Precision 5820 | 7820 | 7920 Tower. You can set this option in the BIOS. Giving the NI MXI system the most slots possible can help.