Thanks very much everybody! There is some really helpful and useful info there - I will make a system image and be done with it. I think there must be something in the Windows Starter disc to limit what you can do when installing.
Anyway - meanwhile I have just installed Windows 7 Home Premium full on my Asus Eee Pc 900 - woohoo! I have spent a week trying to update the bios - nearly killed the netbook, until I found the simple way (using asus update utility instead of usb) - installed supertalent 64gb, disabled 4gb ssd on motherboard, and am currently loading Windows 7 home premium. I am very happy. I love the little netbooks - you can carry them anywhere and my XP will be no good soon. And yes it ended up costing me £130 for the software and £64 for the ssd - but where can you buy a laptop that weighs less than 1kg with Windows 7 on, and has a keyboard? So it's worth it. And I am a real novice - I've just been reading up about things. My original 701 netbook, which I adore, sadly won't run any Windows at all now - not upgradeable, but the 900 is only 1cm bigger.