In my opinion I think all of them are a waste of money. I have seen 2 really cheap laptops both with slower Celeron processors and little RAM running Vista Basic. Both were far too slow for me and if I'd had either I would be either reselling it or it would be left in a cupboard.
If you want a laptop spend a little bit more and get one with a dual core processor and 2 gig of RAM. If you can find one that meets that criteria for £299 then great otherwise forget it.
Others may disagree but in my opinion there reaches a point when something is just too cheap and going under £300 for a laptop is too cheap as its too slow and has too little memory. Under Vista I am talking about. If its XP then it might be not too bad but there hardly any XP laptops still for sale and even if it had XP I still would want to see how fast it worked before purchase. £300 is not a lot for a laptop and for an extra £50 or £100 you can get something thats miles better.