error using edmk and rfid?

hi i'm new with this of mobile development, and i have a problem with the emdk 2.5 c#,
the thing is when i call the method connect() of the class RFIDReader i get this error 
Unable to load the DLL 'rfidapi32pc.dll' i search this file and is in this path C:\Program Files (x86)\Motorola EMDK for .NET\v2.5\Integrator\PC\Driver, i'm using the example that came in the help file of the edmk as a guide.

i tried adding as a reference but i got this error:

A reference to ´C:\Program Files (x86)\Motorola
EMDK for >NET\v2.5\Integrator\PC\Driver\RFIDAPI32PC.dll´
could not be added. Please make sure that the file is accesible,
and that it is a valid assembly or COM component.

please give me a hand with this, thank