Windows Recovery Console Complication

Hello,

I have recently made an error while attempting to rid a friend's computer of a trojan. It is not help in removing the trojan that I now require, rather I require technical knowledge that may seem basic to the MajorGeeks. After using the Windows XP Recovery Console, I reinstalled the operating system after selecting the option to backup the previous operating system files. I now have a folder in C that is titled My Backup. Within this folder are several folders from the previous (I assume lost) operating system (which was the same version of Windows XP), including a folder titled Windows.

What I would like to know: is there a way to replace the new operating system Windows folder with the Windows folder in My Backup? If so, how do I do this? (I want to take every precaution necessary, and I am no expert.) Secondly, is there any easy way to quickly reassign all of the old program files etc. located in the My Backup folder?

I have essentially reinstalled the OS in error, due to advice from the Norton website in removing a trojan known as Boot.Mebroot. Because Norton 360 V3 does not seem to remove this trojan, I referred to the Norton site to see if there were any extra steps I could take. Obviously I messed up, and perhaps Norton did too in providing such unclear information.

At any rate, I would greatly appreciate any help those of you at MajorGeeks can provide. You have helped me greatly in the past. The one million dollar question: can I restore all of the files in My Backup onto this new operating system?