Stoney - on your issue, the standard setup page of the Bios will have a "boot order" section or the like - if you do install a new hdd, just make sure that SATA is on the list somewhere (preferably at the top!) and the bios will track down windows somewhere...
Onan, if you're lucky, you'll have a second IDE socket on your motherboard, next to the first where your cd drives are plugged in (it has to be the same size, one that looks similar but smaller is for your disk drive)... If you do have one there, rob the cable off your old pc and install accordingly,
failing that, you may have to sacrifice a cd drive for the extra hard disk. If you want to do that, you can get an adaptor that will allow you to (securely!) fit your hard disk into the larger bay where the cd drive now is.
Failing that you can buy an ide>SATA convertor
http://www.scan.co.uk/Products/Produ...oductID=176415
or failing that, you can convert your ide hard disk into an external usb hard disk with one of the following:
http://www.scan.co.uk/Products/Produ...ilterKeywords=