when it comes to laptops, HP and Sony Vaio are the best ones for me. But now brand Sony Vaio is not any more. I'll suggest you to go with HP. As per your requirement you want Windows 7, i think it'll be somewhat difficult to get Windows 7 these days on new laptops. As there's is difference in the keyboard of Windows 8 and 7. If you'll install windows 7, You may find it difficult to ON/OFF Wi-Fi and Bluetooth from the keyboard. Because Windows 8 keyboards does not provide any button/key for ON/OFF of Wi-fi and Bluetooth, they are always in ON mode and Windows 7 need command from any button or key to ON/OFF Wi-fi and Bluetooth (Not in all laptops, this problem arising in few models)
anyways here's one
Model- HP R-033
Processor- Intel i3
Ram- 4 GB
Hard Disk- 500 GB
Graphics Card- 2 GB Nivedia
Screen - 15.6 inch
you'll get it between 29000-35000 on different online shopping websites. Amazon is providing it at 29000