Upgrade to Windows 10 question

[Megazero]

So... I'm working as a programmer and developing web service and so on using Node.js. I'm not entirely sure why but when I install 8.1 and then upgrade to Windows 10 on a new laptop whenever I run node npm install I got BSOD. (dont worry this is not a question on programming problem), so I downgrade back to 8.1 and found out that even that took some try to get the node to finally work again. So now I want to try upgrade to 10 again but I'm afraid it might broke my Node JS again.

So  my question is: If I upgraded to Windows 10 now and it go wrong, when I downgrade back to 8.1 using the Windows Update>Go back to 8.1 thingy, will it return to exactly the same state I am at right now?

[EpicAdom]

So... I'm working as a programmer and developing web service and so on using Node.js. I'm not entirely sure why but when I install 8.1 and then upgrade to Windows 10 on a new laptop whenever I run node npm install I got BSOD. (dont worry this is not a question on programming problem), so I downgrade back to 8.1 and found out that even that took some try to get the node to finally work again. So now I want to try upgrade to 10 again but I'm afraid it might broke my Node JS again.

So  my question is: If I upgraded to Windows 10 now and it go wrong, when I downgrade back to 8.1 using the Windows Update>Go back to 8.1 thingy, will it return to exactly the same state I am at right now?

You should be perfectly fine with downgrading if necessary