Backdoor.Tidserv!gen4 on Windows 7

I have had the Backdoor.Tidserv virus for close to  a month now.  I purchased Norton Antivirus in hopes that it would get rid of the virus, but it says I must manually get rid of it.  I tried following the instructions online, however they arent specific to Windows 7, and a lot has changed in the new OS.

 

Would anyone be able to assist me in getting rid of the virus?

 

THanks