How can I fix the malfunction Start menu, MS Edge, Store, Calculator in W10 ?

[WPCentral Question]

I tried some solutions found on the net but did not work either.(This situation arose after 2 months of upgrade)
Eventually, I can reinstall W10 ? (but I do not have product number from initial W7)

 

[cmakthat]

What isn't working exactly? The apps just don't open?

Usually laptop manufactures include a "factory restore" for you to reset your laptop back to how it originally was when you bought the laptop. If that's the case, then you won't need the product number. You could also download an application called "ShowKeyPlus" for Windows and it will display your product key for you to copy down.