No default gateway

I am having a problem with my other computers default gateway. it is not there, and I have pretty much been through EVERY single step to deal with this issue and it does not work this time. by saying this time I mean this isnt the first time it happens, however the 2 other times it got fixed in the end. this time the same ways to fix it does not work, even though all the 3 times I've had it, it is only the default gateway that is gone and instead of the original name on my network, it says "unidentified network". my computer is wired.

I am not good at dealing with this kind of issues just to put that on the table.