Hey haven't been here for years good to see they kept my pass and name! Enough celebration, Just loaded X3 and most  of the goodies, I see everything but XLN in the Plug-in manager, I've tried to assign the path in Plug-in but nothin. Win 7 /32  ultimate.
XLN runs stand alone can even drag 8 bar of samples and drag midi but get no play back from XLN, obviously cause X3 dosn't see it.
 
 Here's the weird thing XLN installed into C:\ProgramData\Microsoft\Windows\Start Menu\Programs. I just let it go where it wanted to.; All other add-ons went to C:\Programs; At first the C:\ProgramData was hidden, not any more. Now I'm afraid to try and uninstall. because of the, one time install option that came with X3.
 
I almost want to go and system restore and start all over again but the dreaded one time option has me fearful! One final thing I did see an error when loading X3 that it couldn't find a file but I didn't write it down ( STUPID DUMMY}. I've spent hours gleaning the net and trying all I could think of, Just want to play Guitar and make some Music and love The XLN Addictive Drums. Help! 

The Start Menu location is just that, the start menu. I would be surprised if the software actually loaded there. Usually XLN installs their software in the "C:\Program Files" directories just like everyone else. C:\ProgramData is a hidden directory and typically contains configuration information. I would image the VST dll is in the "C:\Program Files" directory tree somewhere. I never take defaults when installing software and did not notice XLN default plug-in path but it should be easy to scan for "Addictive Drums" in "C:\Program Files" to file the dll location.

AHHHH! Got it to go in found it in C:\Programs\ VST weird cause melodyne in there Sonar it found it. I don't Know if me hitting the XLN online installer again for about the 5th time it loaded it. Great Googlly Moogly.