new pc wont work on the internet

[buhio67]

i got a new pc yesterday it has 8 gb ram, an intel core i7 4790, a gtx 980, a b85m-g motherboard and a 600 b psu
it cost me 900 and it doesnt work
when it 1st booted up it ran perfectly and it was running the internet great but then it started being really slow on the internet and now it wont work at all
im using a wireless dongle wich works on everything else in the house and i have tryed an eithernet cable but that didnt work
any ideas?

 

[boosted1g]

Troubleshoot with Ethernet to eliminate the WiFi variable.

When you are plugged into Ethernet do you get an ip address? Open a command prompt and type "ipconfig" you should get an address that starts with 192.168.x.x

Have you scanned for viruses?