Are you installing from Download or Disks?
Disk1 is the Program Files and GR4
Did it put the GR4 Icon on your desk top?
Im really not understanding how you are trying to use it.
If I select just the Icon and launch GR4 only, it works that way;
To insert it as a plug in x64-
On Tracks--I right click in the FX Bin>Audio FX>Amp/Tape Simulation>Guitar Rig 4
On Busses--Right click FX Bin>Guitar Rig> choose 32bit or 64bit and select from there
The GR4 File is showing 56.7mb on the icon in its folder
All I have installed on my system is x64-No 32bit at all
Curious to see what ya come up with, keep us posted