I reccomend getting a new laptop, so you get the warranty etc. Also, it means that you can use the laptop for longer, since older laptops tend to slow down when running new programs, or fail simply because they are old. For same price,, that lenovo G50-70 could last much longer than the dell, and since its on windows 8.1, you shouldn't have any software incompatibilities. (also, windows 8.1 machines will get a free upgrade to windows 10, while windows 7 user may have to pay a fee). The dell also may not run windows 10 as well as the lenovo.