PC still not working after system Recovery

I have been trying to fix a friends pc and ran into a few problems it is an Advent T9002 tower running Windows XP home. When he first brought the pc round, It would ask for the system Recovery Disks, these failed, saying "unable to format user partition".

I then checked his Maxtor HDD using PowerMax this came back with the error of Partition table corrupted, I rebuild the Partition Table using Active@ Partition Recovery 3.0 (DOS version).

I was now able to use his system recovery disks these seemed to have worked, and replaced all the system files but when the pc rebooted it just hangs at the boot for cd prompt. I was then able to get the pc boot into windows but using a boot CD (I can not enter the RC to rebulid the MBR).

Now the taskbar is just off screen. I can just about click the top and it is not locked, I also cannot move any desktop items (auto-arrange is not on) or copy any files form CD (CD drive only works in Safe Mode). I tried Taskbar Repair Tool which gave me a Runtime error '462' (I think)

So to copy any files to has HDD I have to connect it to my PC. I have ran an Avast! scan which got a few trojans. When his HD was connected to my pc I found a Worm on it using AD-Aware. I have now gone through the steps off removing Malware but must of these programs will not install on my friends PC I get a "Windows Installer Service could not be accessed" error on a few of them. I then followed the instructions here http://support.microsoft.com/kb/315353
but to no avail

I would like to know if anyone has any other ideas bar a reinstall

Thank you very much in advance
(sorry about length and if any more info is needed I shall try to supply it)