Native Instruments' Guitar Rig audio effects plug-in doesn't generate any sound on its own; rather, it modulates the sound from another instrument to simulate the effects of hardware guitar amplifiers, pedals and effects boxes. To load Guitar Rig into the Cockos Reaper digital audio production software, you will create a new instrument track and then apply Guitar Rig to it as an effect. Guitar Rig comes in two versions: the limited but free Player edition and the full Pro version.
Launch Reaper. Click the "Insert" menu, then click "Virtual Instrument on New Track."
Navigate to the instrument to which you want to apply Guitar Rig. Double-click on the instrument.
Click "FX" in the instrument window that pops up. Type "guitar" into the "Filter List" box at the bottom of the window that opens.
Double-click "Guitar Rig" to load it into Reaper.
If Reaper can't find Guitar Rig, add the Guitar Rig directory in the "VST" part of the program's "Preferences" section.