Trojan found, cannot be cleaned

[DM Cross]

So my girlfriend's father has a computer in his home and it suddenly started slowing down on him. He asked me to come down and help him and I think I've found the problem.

Someone downloaded a Trojan through Limewire and I've deleted it and trying to clean it is impossible, now that it's been deleted. Obviously I need to get the Trojan out and am looking for answers other than rebooting it due to the fact that it's a household computer with multiple people's personal and business operations on it.

What are my options?

 

[FireCat]

if you know the name of the trojan, then you chould search after a remover for just that trojan. can take some time to find it. But try that first.

 

[Prometheus]

What antivirus is currently installed?

 

[holy_spirit]

I got something like that before,
if this Trojan has some issues in system32 folder you have to clean them
go to your system32 folder, display contents in a groups and sort them by "Data Modified", try to locate the responsable dll that cause the problem (the data modified for it must match current data or less than a bit)
download this unlocker program, and unlock the individual dll, then delete it

hope this helps

 

[Slapshot136]

try a boot-scan with an antivirus