I was once told NOD32 is the best antivir available right now, so I installed it on my dads pc to get rid of the trojans.In the installation I kept everything intact, changed nothing from the default options, scanned found the trojans, cleaned it up really good, and then....the pc was out of the network. It refused to find the network, the ip(i think) had been changed, and since the technicians there aren't exactlly the experts, formated it. So I avoided installing it on my pc since then. But I really want to install it withought losing ip's or anything. Is it possible?

Well, "the best antivir available rightnow..." may be a little bit of an over-statement but it does seem very good.

http://www.pcmag.com/article2/0,1895,1720842,00.asp
http://reviews.cnet.com/NOD32/4505-3...9093349-2.html

I don't quite understand what you're saying about the IP address - are you suggesting that this piece of AV software actually altered the network IP address on the PC on which it was installed?

Yes it seemed this way. Of course I cant know if suddenly a trojan did this, but before installing nod32 the pc was on the network. After it not. In the installation it mentioned something about sockets I think, which I ignored, left default and pressed next

Is the IP address DHCP (dynamic)? or Static (i.e: you type it in)? Either way, you can make a note of the IP address, subnet, gateway and any DNS entries before installing NOD32 and then when installed, if anything changes then you can revert back to your recorded details.