trashVin,
Gpib-32.dll is a standard win32 dll. You do not need to register the dll to use it. Typically, when you want to communicate with a GPID devise, you should install our device <a href="
http://joule.ni.com/nidu/cds/view/p/id/335/lang/en" target="_blank">driver</a> and use the higher level functions. Gpid-32.dll is the lower level dll that you typically do not need to access directly. If you are sure you need to access it directly, then this <a href="
http://zone.ni.com/devzone/cda/tut/p/id/3454" target="_blank">developer zone</a> article is a good point to start.