Why do you need to upgrade then? Is the shyt just too old or something? You can dual boot into windows with that shyt no problem.
What about
Acer Aspire E 11 ES1-111M-C40S 11.6-Inch Laptop?
Truth be told, I don't think I have enough space for dual boot. I also don't want that crapware near thy OS X. My major also requires us to use Windows