I have a trojan horse virus that I cant get rid of!!!!?

I ran avast, avg free, and adaware. Avg finds it, but it dosent seem to get rid of it, it says it is in net dde.exe Please help!!!!!!!

I have a trojan horse virus that I cant get rid of!!!!?virus scanner

STEP 1: SCAN COMPUTER FOR INFECTIONS

1. The most important thing you can do is make sure you know what you鈥檙e up against. Run these online scanners to help figure out what is infecting your system:

-http://housecall.trendmicro.com/

-http://www.pandasecurity.com/homeusers/s...

1A. clean up using internet options [ XP %26 Vista are the same ]

delete cookies/history/temp files from internet options general page

2. cookie management [ XP %26 Vista ]

start--control panel--internet options--privacy--advanced--override

select:

allow 1st party cookies

BLOCK 3rd [ tracking ] party cookies

3. clean up windows folders

empty prefetch and temp file folders

start--control panel--[ XP %26 Vista ]

local disk drive (c) [ XP ]

O.S. (c)--windows [ Vista ]

temp folder--

[ XP ] file,[ Vista ] organize

XP %26 Vista

select all

press delete key on keyboard

STEP 4. TURN OFF SYSTEM RESTORE

now go OFFLINE and power back up under SAFE MODE.

while booting up,press f-8 key till you get SAFE MODE utility selection