Solution
Agilent IO Libraries 14.1 overwrites a portion of the National Instruments NI-488.2 driver when it is installed. The installer renames NI's GPIB-32.dll file, located in C:\Windows\SysWOW64, to GPIB-32.ORIG.dll and copies Agilent's GPIB-32.dll in place of NI's GPIB-32.dll.
Note: Agilent IO Libraries 14.0 and prior versions do not exhibit this behavior and thus should not produce this problem.
If you want to use your NI card on a machine that still has the Agilent and NI GPIB drivers installed, use the following procedure:
- Launch the Agilent Connection Expert
- Select Tools» Options
- Select the Agilent 488 Options tab
- Uncheck the Use the Agilent 488 driver library where possible checkbox
The Agilent software should no longer overwrite your NI GPIB-32.dll with Agilent's version.
If you want to use Agilent and NI boards at the same time, refer to Using Both NI GPIB and Keysight HPIB Controllers in the Same System.