In my opinion, you are unable to use an OS that started out on Pi2, and run it on a Pi3. At least that is what my experience with it told me. I spent the time to upgrade wheezy to jessie, then swap the microSD card, and no go.
A fresh install of jessie is needed. Here is how i did it without using noobs.
1) Obtain the flavor of jessie that you want, full or lite, from the following link
2) Format your microSD card for FAT32.
The following is for Windows install.
3) Using the image mounting tool, Win32DiskImager, mount the img file to your microSD card.
https://www.raspberrypi.org/documentati ... windows.md
4) Place the newly loaded microSD into your Pi3 and power it on.
Image mounter for other OS can be found at:
https://www.raspberrypi.org/documentati ... ng-images/