Active 0x7c91b21a - told it might be an infection

Going back to your initial post ....

Googling various parts of your first error message suggests that malware may well be involved.

A repair install of the OS may permit booting into Windows to enable the system to be cleaned up, but that is by no means certain.

AFAIK the Dell CD is a full install CD and will allow a repair (non-destructive) as opposed to a Recovery (destructive - total data loss)

What is the history behind this problem? Did it occur suddenly or after you had added hardware or software or visited a particular web site (P2P?)?

 

I started a reply and fell asleep

OS is an abbreviation for Operating System

AFAIK is an acronym for 'As far as I know'.

From your first post you say that you cannot boot into Safe Mode so System Restore is not an option.

At this stage I think the only option open is to try a Repair install of XP although I am not convinced that it will solve the problem if it is hardware related. If malware related it may get you to the stage where broni can assist.