Looking for cheap laptop?

For videos and minor gaming (gmod. Minecraft, rollercoaster tycoon etc) so far i have this one as my top pickhttp://m.staples.ca/en/Lenovo-ThinkPad-T420-4180AP3-Refurbished-Laptop-14-Intel-Core-i52520M-25GHz-4GB-RAM-500GB-HDD-Win7-Pro-English/product_1866867_2-CA_1_20001?langId=1
Think this woukd be fine?

Which laptop should I purchase for my major?

I intend to study computer science and was wondering what laptop should I purchase? Should I get a Lenovo Thinkpad or a macbook air/pro? I want to use the computer for other things as well besides school.

Can I install windows 7 64-bit on my Lenovo s10-3s?

I have a Lenovo s10-3s ideapad. Its specifications are: Intel Atom Processor, 2gb of ram, 500gb HDD.

When I open system properties, it says, "x64 based processor". So can I install win 7 64-bit or not? Or any other 64-bit windows?

Can my laptop run Counter Strike: Global Offensive?

I was gifted a laptop and was wondering if it could run Cs go. Its a Lenovo Ideapad Yoga 13.

Processor: Intel Core i7-3517U CPU @ 1.90GHz 2.40GHz

Ram: 8.00 GB

GPU: Intel HD Graphics 4000

System Type: 64-bit Operating System, x64-based processor

In looking for a laptop under 400$ that meets these specs?

Processor (CPU): Intel i5 or i7 / AMD Athlon X2 or better
Graphics: ATI Radeon HD (non M or Mobility) / nVidia GeForce 1xx/2xx/3xx/4xx/5xx/6xx (excluding M / Mobile or Go)
Memory: 4GB DDR3+

I'm looking for a laptop under 400$ that meets these specs.