My internet wont work?

[a random guy]

I stopped using my computer for more or less a month because I needed a new laptop screen and I finally got it delivered and fixed it myself (Almost flawless) and when I turned it on it done some repairs all understandable. After the automatic repairs it ran, I turned it on again and then it worked what appeared to be normally. The internet was off (I done that) and now I had to turn it on and off a few times to get the internet back on, but when I try to go on the internet, it won't connect (DNS won't work) So then I went and diagnosed the connection like I normally do, and then I find "The Diagnostics Policy Service is not running". I then try to repair as a administrator and that won't work.. So I guess this is 2 questions in one.
1) How do I turn on "The Diagnostics Policy Service"
and..
2) Why wont the internet work and how do I fix it without diagnosing the connection unless the answer to question 1 is given.

Thanks.
When I try and run the diagnostic thing it says it can't for the Local Computer.. I am REALLY confused.. Please someone help c: