I would suggest you go with any Dell laptops. Since they are durable.
And there are plenty of Dell laptops, which comes with a feature to upgrade your RAM. I believe you don't need much of graphics. So choose any laptop that has at least 1GB graphics card and i5 or i3 processors.
So IMO, below should be ideal for B-schools for 2 years or even for other stuff per se.
1. RAM-4GB(minimum) or 8GB (preferred)
2. i3 or i5 processor. Latest generation ones.
3. 1 GB (minimum) or 2 GB (preferred) graphics.
4. 1TB( sufficient) or 2TB hard drive. I feel 1TB should be sufficient since you can buy portable ones.
5. 14 or 15-inch HD screen
6. HD Webcam
It goes without saying Bluetooth and WiFi inbuilt.
And below list can be good to have.
1. Backlit keyboard.
2. DVD drive (laptops nowadays doesn't have DVD drive by default)
P.S. I feel Dell Inspiron series are really good. They are durable and lightweight. And battery life is good. Solid 5-6 hours of continuous usage in Balanced setting.