Der Gothmann

I have recently built myself a new pc. It has a p5q motherboard and a quad core processor (I don't know if this is relevant) and I have just booted it up for the first time. I am using a hard drive from my previous pc (so I don't need to do everything again) and it has XP professional on it. For the first time ever, as soon as it starts booting up windows, It tells me that I must activate it to log in. I have several problems with this: 1. I do not have any serial numbers or information about my copy of XP (But it IS a legitemate copy) 2. The person who built it does not have them either as he constructed my old pc out of second-hand parts and the hard drive already had XP on it. 3. Even if I could get hold of the information, the pc does not recognise my keyboard or mouse outside of DOS or BIOS and I must be able to log in to use them. 4. I can't log in to use them without activating windows. 5. No internet software is present on my pc presently and neither is the software for the dongle I intended to use. Either way, I cannot connect to the internet or install the software without logging on and connecting. 6. I can't log in without activating windows 7. I can't activate windows without the mouse or keyboard 8. I can't activate the mouse or keyboard without logging on and registering 9. I can't log in without activating windows... As you can probably guess, I seem to be in quite an infuriating circular dilemma as ANY one essential requirement needs the other two to already be working. I have never before been connected to the internet via this pc nor been asked to register windows before. Do you think this is an addition to some pre-installed software in the chip or the motherboard? Or is it merely a ruse to force me to buy a new hard drive, buy windows vista, install vista and register that? (this would obviously cost a great deal more money than I had in my budget to begin with and would not arrive until monday - not an option.) I am in a considerable rush so any help would be immensely appreciated.