Advice on $600cdn Gaming PC

Hardware Hub Build a PC
1

Just looking for advice on a build another user suggested to me.

http://pcpartpicker.com/user/jeezlouise/saved/1UEC

Is their anything I should change?

What OS should I use for old and new games?

Thank you.

 

2

http://pcpartpicker.com/user/deejeta/saved/1WoI

includes win 7

3

The computer would cost $920 in Canada.