An update of popular GK Amplification plug-ins - version 2.1.0 is now available with new features:
- 64b plug-in versions added.
- VST3 and AAX plugins formats added.
- User presets handling improved for better portability.
- GUI functionality improved.
- Standalone version is completely rewritten and includes metronome, recorder and advanced audio file player
 
http://www.audiffex.com/EN/gallien.html
 

FWIW, I had trouble in Windows 8 with the installation. I had to MANUALLY TYPE IN the registration number before it would move to the next window to install. I tried copy and paste and it just would not work. After the install everything is buttah! This has always been my goto bass amp and I am so glad to see it move up to 64 bit.