Activation key limit exceed can not user any more.
On Dragon Medical software please check if you are entering the correct key of Dragon Medical software,
If not then enter the correct key.
If yes they check if you have used this dragon key for multiple times.
You have only 5 activations available under one Dragon Medical Practice Edition 4 key
So if your 5 activation is already done they you need to purchase the new key.
If you are using it first or second time and dragon gives you this error, that means there is something wrong with the key activation process.
You have 2 options to reset the key, first one is call Dragon Customer service.
Second you can do this manually by clicking this link. http://activation.scansoft.com/us