allow options for other operating systems.
I was wondering why the only Windows operating system available was Windows 8. It seems like a large number of people wish to stay with Windows 7, myself included.

That would be because despite the anti-windows 8 circlejerking which often goes on on reddit, it is the superior OS in almost every way.
The only downside is that metro can be annoying. However there are third party applications to disable it if you want to install those!
No sense in paying the same amount for Windows 7 if you can get 8.
Please keep in mind that this shouldn’t be the extent of your research. Feel free to customise parts further based on your specific needs.