If you have a look around, there are quite a few laptops that can be bought for around the £300 mark.
There's nothing that I can see on Overclockers at that price so you'll have to go elsewhere - and I would make suggestions but the forum rules don't permit linking to competitors.
However, if you look around for the Lenovo ThinkPad Edge E555, it can be bought for £299 and is specced like this:
AMD A8-7100 Quad Core Processor
15.6" HD Screen
Microsoft Windows 7 Professional 64-bit Edition
8GB DDR3 RAM
500GB HDD
DVD Rewriter
AMD Radeon R5 Graphics
USB3 | HDMI | Bluetooth
Dual Operating System - Windows 7 Pro installed with Windows 8 Pro License and System Restore included
Seems like a good deal - although I'm puzzled by the dual operating system gubbins as most people will probably upgrade it to Windows 10.