Getting sonar to recognize my edrums

I believe your edrums are a MIDI device, so try this...

• Open SONAR
• Go to Edit > Preferences > MIDI > Devices

• Select your MIDI ports under Inputs
• Select your MIDI ports under Outputs
• Click Apply
• Click Close
• Click the + (Add Track) button in the Track view
• Click the Instrument tab
• Select Record Enable
• Click Create

My Yamaha kit comes with a driver so you have to install that first. 
Then as said above you make sure it's checked as an input device on your midi list'
Insert a midi track and select the drum kit as the input device. 
I monitor my drums brain when I play otherwise there is a touch of latency which bugs me. You might fare better if your computer is better than mine.
 

Sounds like you're halfway there. See if this works for you. Substitute "DropZone" for SI Drums and "keyboard" for edrums.
 
Recording MIDI: http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=Tutorial4.3.html

I'm not sure, Thomas, but delays usually means latency. Maybe something here will help?
 
http://www.cakewalk.com/Support/Knowledge-Base/2007013182/Im-getting-a-delay-or-latency-when-recording-or-performing-synths

I've read a number of posts here where people have had good success with WASAPI Exclusive. Also, a dedicated audio interface typically works best. (See this thread for a discussion of USB interfaces and latency.)
 
This guide will help you optimize your PC.
http://www.cakewalk.com/Support/Knowledge-Base/2007013376/Windows-Optimization-Guide
 
It's possible, but not likely, you have a defective unit. ddrum should be able to help you troubleshoot.
 
Customer Service - customerservice@ddrum.com
Toll Free: (800) 793-5273

Well often if there is not a proper driver supplied there will be issues like this. It's important when using a DAW to use good drivers. 
So myself before I buy anything I go to the web page and see what's available under downloads for the product. 
Any product that claims " no driver is needed" is off my list.  I will assume problems. 
 
But maybe your set will work, you say you had it working with LE. 
 
So things to check. 
 
Insert a new midi track. 
Select your E drums Omni as the input device
Select record for the track and make sure the input echo is highlighted. It should always be highlighted when the midi track is selected. 
play your drums and the track meter should be showing action. 
if not you have no or have lost your connection to the drums and that's your drivers, a bad usb cable or?   
if the track meter is showing then move to the next step. 
Insert SI drums And not point the output of the midi track to them. 
They should play regardless of the GUI being open or not.
Just make sure you still have "focus" of the midi track and input echo highlighted.
Now what the track meter and it should still show action and you should still hear the SI drums playing as your strike your drums.  
 
 

Just to be clear, There probably nothing broken about your kit. 
And also to be clear the driver I'm talking about is a MIDI driver which is not the same as an audio driver like WASAPI. But the audio drive does come into play when you trigger a drum VST. 
Yes you will have audio latency most systems , even with ASIO drivers which come with proper audio interfaces. 
It makes it hard with drums. I have enough latency with my set up that is bugs me when I play my drums using a VST drum source so what I do is direct monitor the Digital drum set brain which has no latency. I record the midi that way and then use a VST drum for playback in Sonar. 
 
But that's a different driver, the midi driver is what I'm talking about and that is needed for Sonar to receive the output from the drums via USB and translate into midi data. Without a driver supplied by the manufacturer, Windows will toss in some sort of generic driver,and when you say it worked on the other computer that may just tell us something. Possibly that computer used a better generic driver than your other one did,, just a long shot. 
If it is a problem another solution is I see your drum kit has real MIDI ports which you can also use into Sonar.What you would need is an audio interface with midi ports like the Tascam us 2x2. https://www.sweetwater.com/store/detail/US2X2
 You will want a proper audio interface anyhow, it makes working with Sonar much  much better. 

His issue is Sonar is disconnecting from his drums. He gets it to work when the focus is on SI drums only. 
There is no reason to asio4all anymore, we now have WASAPI. 
And most certainly as I said above, in the end you should rely have a proper audio interface if you want things to go smoothly. And for E drums if your going to monitor a VST drum you will need an interface that is capable of under 7ms of RTL... so an RME, Motu etc. The easy solution is don't monitor the VST, monitor the E drums when tracking. 

Well I was able to change the "Currently Assigned Port" to my edrum. still the same result. As soon as i click out of the SI-Drums window and go to record it just cuts out. My edrums are still getting a signal on the module but nothing in Sonar. If i restart Sonar i get it back, Until i click out of that box again. Being i bought SHS am i able to un-install the program and re-install it? or do i only get 1 download? I would like to download it on my other computer but before i hook everything up i would like to know if i can install it again. Maybe something got corrupt when downloading Sonar. I do remember that my computer did a mandatory restart because it needed a update while i was downloading Sonar.

+1 to not using asio4all under any circumstances.

Is it only me who misreads this thread title as "Getting Sonar to recognise my eardrums" every time I see it?

I use a Yamaha kit and do as Cactus Music suggested - I monitor via the kit's brain and playback via vsti, even though I get around 4ms latency from my interface.

Hope you get it sorted.