Once you authenticate you copy (using iLok) your iLok needs to be in the USB drive everytime you load instruments from EW to the plugin software. This is if you have legally purchased EW Silver, but if you've obtained it through other methods (I'm not accusing but I know how expensive the software is.) Because this IS the process you'd probably have to get EW Gold. (Of course by doing so you lose Choir Voices, Pianos/Organs, and a few various percussions, but the other instrument libraries have more articulations for each instuments.)
A couple of things that may be the actual problem, and I'll cover both legal and "other":
-Your computer might not be able to handle the 64bit version which you could have DLed.
-The version of EW Silver is old so it's authentication methods are faulted. (If yours uses Kompakt it's outdated. PLAY is the VSTi plug-in EW Silver uses (Not sure about gold haven't bought it yet.)
-The version of Kompakt is old.
-CHECK THE FILE PATH. I know this sounds very standard, but cracked versions tend add and extra folder or two and EW pulls from a specific file path if done automatically. There is a way to manually load instruments, but I can't remember how to do it.