Need help to be rid of trojan horse dropper.generic_c.mmi

Hey all, this morning my AVG discovered this:trojan horse dropper.generic_c.mmi
usually when AVG detects a threat it gives me the option of removing it though with this infection the only option that is available to me is to ignore it...
Now I've looked around a few forums and have read that this particular infection turns off security settings leaving your computer vunerable to other infections (computer AIDS). and i am disturbed to hear that it can be a very serious problem. I have since checked my security settings and can confirm that they are turned off and i cannot re-activate them at this point. I've also noticed that whilst typing on the net occasionally the insertion cursor will dissapear or go back a couple of sentences, this is starting to occur more and more frequently which as you can imagine is very annoying!
Whilst googling i was linked to a thread from this site where somebody had a the same virus and was instructed through to a resolution. The thread also stated that fixing this problem is user-specific. So please can somebody help me before this gets any worse i'm a bit of a newb when it comes to dealing with virus' and system files, however i can and am willing to follow some instrution to fix the issue. I am also interested in how this got on my computer in the first place and how i can prevent it from happening again.
Thanks

Link to other major geeks thread:
http://forums.majorgeeks.com/showthread.php?p=1754746

 

Ok I have since followed the instructions on this thread;
http://forums.majorgeeks.com/showthread.php?t=262334

However, C:\MGtools\GetLogs.bat does not exist on my computer. And I still cannot access windows firewall.

here are the logs from hitmanpro and rougekiller;