You can start by booting up in safemode and use a virusscanner to remove the virusses, and a anti-adware tool to remove the spyware/adware...
After that, and you know the system is clean, you can boot up again like normal and fix the internet settings...
Also, on
symantec (company that makes Norton Antivirus) you can always read how you exactly have to proceed to remove a particular virus completely (often involves booting up in safe made and tweaking the registry). They have very detailed explainations for each virus-removal and often also tools to remove a individual virus(family). I suggest you to read that after Norton has detected what type of virus it is...
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