A friend has an XP Home installation on a Time machine which is failing to start properly, it gets to the desktop and then freezes. Because of this I cannot run Task Manager, MS config or anything else that might give me an idea of what is (or is not) going on. The sons of the household promise me that they have not downloaded anything (not too sure about that on past evidence), so I'm not any wiser from that angle either. They have just moved house and cannot find the original documentation and disks which came with the machine (in fact, they are not sure whether a recovery disk exists).
Now for the question - can I use my XP disk to boot from in the hope of getting to the point where I can do a repair install, or is this a no-no because of the one copy of WIndows per machine rule.
You can as long as you use their licence key and not yours. You pay for the licence, the cd is just a copy. It is one licence per pc, it would not activate with the same key as yours. I had to do that with mine on a friends pc who had a similar problem.
I had this recently with my son's system. Repair was not an option in the end as faulty RAM had caused so much mayhem with the system that a complete format and reinstall was the only option. I used my XP disk and his licence key - once I had diagnosed and replaced the RAM it was a doddle; until that time it had been a nightmare. Oddly, this was a Time machine as well.........