What operating system do you use?

[NintendoFan]

I used Windows XP for a very long time(at least like 5 years) but I currently use Windows 7, because 1. XP is outdated and 2. I think I like 7 better.

[MKGirlism]

I'm using:
- iMac: OS X 10.10.x ~ Mainly to Stream Music from.
- Mac Mini: Windows 7 ~ Mostly for Capture Cards, or otherwise, to Manage YamiNet (a little part of Internet, that's only accessible to me, where I put all my Web Apps on, which I have in Development).
- MacBook Pro: Manjaro Linux with KDE ~ I use my Chat Clients (Skype, etc.) on that one.
- Surface Pro 3: Windows 10 and Manjaro Linux with Awesome WM (Dual-Boot) ~ For everything else. My Main PC is a Tablet!

For the record:
Yes, I bought all these Computers as brand new, but I never paid the Full Price for any of them.
In 2010, I bought my iMac with a 19% Discount.
In 2011, I bought my MacBook Pro with a 19% Discount + a 50% Discount atop of it (not really a Discount, it was possible for me to get a some money from the Dutch Government, to buy a Laptop with, because of my disability to write properly, back then).
In 2012, I bought my Mac Mini with a 21% Discount.
In 2015, I bought my Surface Pro 3 with a 21% Discount.

All in the MediaMarkt in The Netherlands (I lived there, until June 2015), they organise a huge Discount on the last Week of January, every single year.