Please help. how can i remove a virus that changed my ip address and wont stop popping up?

This has happened to me before but then I had a warrant and they walked me thru the steps. A box keeps popping up saying it is a virus protection but it.is not. It is called antivira ad. I.think I got it to stop popping. Up but now I can't get on the internet. Last time it changed my ip address. Now i keep getting errors when I try running anything. Also a program svchost.exe won't shut.down. I'm sure its the virus. Please help. Sorry about typos I am trying to use a touch screen keyboard am trying to use a touch screen keybo