Recently I tried to install an X3 upgrade I purchased awhile back, it didn't go well. Had major problems with audio engine stoppage that I could not remedy after trying numerous fixes. I uninstalled and went back to X2 which runs like a charm.....except when I create a new project, the Template menu is missing. I can find the Template folder on the drive, X2 just can't seem to find it. Yesterday I was going to dig in and start learning to do some drum programming with the Step Sequencer in Session Drummer 3 and it won't load despite specifying the folder in the VST scanner and rescanning. I have it loaded in a project from before the attempted X3 upgrade and it shows up and functions perfectly, but can't even be found when creating a new project. Any thoughts before I do a clean reinstall? Thanks.

Hi. Did you install the X3e update?
https://www.cakewalk.com/Support/Knowledge-Base/2007013361/SONAR-X3e-Update
All the best.

Yes, tried the X3 update, staying with X2 which is much more stable on my system except for the specific glitches in my original post, which only occurred after the X3 attempt.

I've seen similar post suggestions, seems I'm not the only one to suffer this problem and since I can't locate a setup.exe file anywhere to attempt a custom installation of just what's missing, an uninstall/clean install is my fate. Grrrrrr.

Have you tried to do an advanced install?
You should be able to install some of the features, without having to reinstall the whole package.
It comes up as an alternative during the installation process. 

I can't locate the setup.exe file without extracting the whole digital download package. Scott Garrigus jolted my memory, I use Acronis True Image and have a clone of my master drive. I can reset the entire drive in about a half hour, will take far less time and effort.

Best of luck to you.

Thanks.

river
I can't locate the setup.exe file without extracting the whole digital download package.

The Digital download came in sections, Sonar PT1 / Sonar PT2 / Loop content / EXC.. 
you simply take the original Sonar X2 PT 1 or X3 PT 1 install and do an advanced install like Ken mentioned.
When you being install just go to advanced and select only session drummer.
 
This will take less than 10 minutes Vs total reinstall which typically takes a lot longer than 10 minutes if Windows, Sonar and other plug ins are  installed.
 
It was a known issue that session drummer 3 would disappear in some cases.
I believe it was X3.

Thanks, will try that.