Trojan Removal Help

Hello all, new to the forum. First of all thank you for the "Read and Run Me" guide on scanning your computer in safe mode etc. Unfortunateley my problem has not been solved by doing this. I have also tried disabling system restore to get rid of the points but nope. My problem is as windows loads and I see my desktop..bang..Avast! pops up, there's a virus called trojan-gen{other} which always appears even when I delete it, next time I restart my pc it re-appears. It's basically the same with ad-aware, it always finds a W32,Trojan.Downloader when I scan..everytime I scan when I start my computer up so it seems to reappear on boot-up?

any ideas on to get rid of these permanantly.

Thank You in Advance

P.S The programs I have are...AVG, ZoneAlarm, Ad-Aware, Avast and S&D.

(edit) pc info...if required -

Microsoft Windows XP Home Edition
Intel Pentium 4HT, 3200 MHz
L2 Cache - 512kb
1024mb DDR RAM

 

Apoligies, won't let me edit it.

My hijacklog..

 

actually I'll leave it.

Thank You anyway

 

Either that or get another post like your previous? nah

Note: may have fixed the problem anyway..