There is also the issue that most Win 7 machines will not have a graphics card that supports DX12 so that will have to be upgraded as well to take advantage of it.
It might be wise to read the article in the link I supplied. You may be surprised what will work
The article supports exactly what I said and has nothing I didn't already know. Only the newer cards like the AMD GCN next ones and the Nvidia Fermi ones will support DX12. Computers that were made for or were shipped with Windows 7 very likely will not have such recent cards unless they were upgraded. For AMD, only the R9 270 and above cards will support DX12. My laptop that was made in 2011 and has a first generation A8 APU will not run DX12. The machine will have to be from the last couple of months of 2013 or later to have a chance at having a compatible graphics card unless, as I said, it has been upgraded by the user. Almost all Windows 7 machines were made earlier than that.
My graphics card is Nvidia GeForce GT 630M and when new version of the graphics card driver is detected by Nvidia GeForce Experience I update it. So is DX12 supported for my graphics card? I bought my laptop on 2014 so I will be able to upgrade my Windows 7 to Windows 10 right?
As Bob said, age has nothing to do with it as long as you're not expecting the graphics features of DX12. If you're satisfied with DX11 (and there are now rumors that some of the DX12 features will be able to be programmed by developers for DX11). In my opinion, given all of the new features and enhancements (DX is just one of them), it wouldn't make much sense not to take advantage of the free upgrade. If your computer runs Win 7, then it can definitely run 10. It's also a way to extend the service life of the machine. Those in the gaming community should definitely go to 10.
As for your card, the GT 630m belongs to the Fermi class and this is a quote from Nvidia;
NVIDIA will support the DX12 API on all the DX11-class GPUs it has shipped; these belong to the Fermi, Kepler and Maxwell architectural designs
.
Therefore it should support some but maybe not all of the DX12 enhancements.
There is also this article to consider;
http://www.polygon.com/2015/1/22/7874793/directx-12-wont-require-a-new-graphics-card-after-all