I know they have a bad rep from people who have never owned one but Dell can be good value and well built for the £300 mark, if you buy one at that price point get an SSD to bang in there too as it will benefit nicely compared to the ones they usually put in there.
Also windows 10 is good IMO I don't know why so many people are having problems with it or what they were expecting when switching to a brand new operating system, in many ways it's slicker than windows 7 and faster loading for a lot of things, more suited to SSD's too. If you are buying new it means you are starting from scratch anyway, most of the problems people are having is with the upgrade from 7(I've done that on my main PC and from scratch on another machine) and expecting all your programs and drivers to work perfectly without some manual updates(most of the updates were done for me for a change it used to be you had to do it all yourself) and maybe having to find alternative programs that play better with windows 10 until the software vendors themselves provide the updates. I thought everyone knew when you move to a new operating system not everything will be 100% compatible. Windows 10 is working great so far for me and I can see it surpassing Windows 7 as my favorite as they inevitably improve upon it.