Securing Precompiled FPGA Extention Bitfile Locations

Updated Nov 9, 2020



  • PXIe-5840
  • PXIe-5644
  • PXIe-5645
  • PXIe-5646
  • PXIe-5171
  • PXIe-5172
  • PXIe-5170
  • PXIe-5820



My FPGA Extension bitfile default location is easy to move around because it is not in an administrator secure location. Is there a way to change that default location to a more secure location?

When you install driver support for a Software-Designed Instrument (SDI), model-specific folders are created in the following location: 

Windows 10/8.1/7: Users\Public\Documents\National Instruments\FPGA Extensions Bitfiles

Here is an example of some of the folders you might see:

These locations are used by the driver when calling a Bitfile as part of an FPGA Extension to a driver session.
In order to change the location where the driver will look for the Bitfile, you have to modify the Registry Key value name for UserBitfilesDir to your desired location.

To modify the Registry Key, please follow these steps:
  1. Run regedit.exe from the Start Menu.
  2. The locations of the registry keys are going to be different based on the module and OS. The following locations are for 64-bit Windows, the 32-bit location will be the same without the \Wow6432Node\ folder in each path. 
  • ​NI PXIe-5840: 
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\National Instruments\VST20​
  • NI PXIe-5644R/5645R/5646R:
 HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\National Instruments\VST
  • NI PXIe-517xR:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\National Instruments\NI-SCOPE\FPGA Extensions Bitfiles​
  1. Edit the Registry Key value name for UserBitfilesDir to your desired location.