harddrive image infected

Hello
I just had to reformat my harddrive, due to a nasty bit of malware, and now have windows up and running and have downloaded and installed all the windows updates and device drivers (I think).

Now, all my old files are held on an "image" on my portable harddrive - in a set of .arc files. I can't remember what software I used to create that image, but I imagine any program that unpacks .arc files will do.

However, I am a bit nervous as I know for sure that the original malware which caused the problem in the first place is also on that image, since I made that backup image right before my computer crashed. So...can someone please help me in the process of unpacking the image and retrieving my files, without inadvertently transferring over the malware?

For detail on the malware, and the problems it caused, please see original thread:

http://www.malwareremoval.com/forum/viewtopic.php?f=12&t=51993

My specs:
Intel® Core ™2 DUO CPU
E4600 @ 2.40 GHz
2.39 GHz, 3.00 GB of RAM
Physical Address Extension

OS:
Windows XP Home Edition
Vers. 2002
Service Pack 3

Thanks