how can i fix my toshiba model number pspaoe02502en?

i seem to have some sort of virus on my laptop which is making it increasingly difficult to use the internet. it is either starting about 50 extra tabs or telling me that it is not connecting to the internet properly. i have tried numerous anti viruses and they all dont seem able to remove the virus. i think its a trojan. trojan vundo and trojan gen are a couple of the viruses detected but not been able to remove them. would like if at all possible to either resolve this or completely reset it to factory settings.