Hello,
I'm sorry, I wasn't able to find a driver for the Tektronix 2221A scope on our instrument driver website at www.ni.com/idnet. Where did you get this driver? Also, is this a driver for LabVIEW or LabWindows? If you downloaded it from Tektronix, please refer to their technical support resources for assistance.
Thanks,
Scott B.
Applications Engineer
National Instruments