Sorted it now, thanks

Good, sorry I had to leave for a bit. If you want to use MIDI control with either Revalver or TH2 Producer, you need to:
go into the plug-in manager,
highlight the plug-in name in VST effects,
open the plug-in properties and
check "Configure as synth"
 
That has the side effect of moving the plug-in from the effects list to the synth list.

Thanks my friend, valuable advice

That's because Revalver and TH2 are fx not instruments. They are for processing audio signals.

Woops! Seems I misunderstood the problem.

Sonar 7 install. If any plug ins are missing, you can re-install Sonar 7, "minus the program files", it lets you choose all the plug ins you would want to install. I assume that is the same for X2 if you have the disc. I know that it is the same for Sonar 4. If you added them at Cakewalk, you should be able to download them again from your account.
 
I recently re-formatted my pc, and therefore went back and re-installed all the plug ins from Sonar 4 and 7, so this is an option. I did not have to install either program files for 4 and 7. However, the guy that answered set them up for synth is correct, and the other reply they are FX not instruments is also correct. TH2 Producer will show in VST Effects folder, I am not sure on Revalver. An install or upgrade should not delete any previous plug ins. But, I have read where some only work as 32 bit.
 
In your plug in manager, it is also a good idea to exclude plug ins that do not belong there, to avoid ever clicking on bad plug ins that do not work in Sonar. Just click on them, and you can drag over the list, and exclude what you don't want in there.