Hello!
Thank you for posting in HP support forums!
You have bought very nice computer. Congrations for the good choice.
Please, note that Windows 8 is the only operating system one officially supported for your computer. Windows 7 is not officially supported.
Since Windows 8 came preinstalled, if you try to install Windows 7 x64, you are going to loose your Windows 8 license. Please, also note that even if Windows 7 may work, it will not be officially supported by HP and if you encounter software issue, HP might require you upgrade to Windows 8.
Although I do not recommend you downgrade to Windows 7 (unless there is some very important business critical reason), if you want to install Windows 7 x64:
- you need to first create recovery discs as per instructions here. You can use them to restore your computer to factory default settings (reinstall Windows 8) if you decide you need to.
- you will have to disabled Secure Boot and the enabled Legacy Boot mode - instructions can be found here. Then you need to configure the machine to boot from DVD disc (this is done from the BIOS).
- You can try to install Windows 7 and let is see if it will recognise all your hardware automatically and if you experience issues and if you need to install some driver, you can try with Windows 8's equivallent for this machine (link here)
Many people do not like Windows 8 and are very shocked with first Windows 8 experience. However, Windows 8 is very good operating system (especially on touch enabled devices). Many people do not like the new way of work, but if they take some time, they at the end find it even more convenient. Windows 8 is a lot more fast and stable than previous Windows versions, Windows 8 include literally thousands of improvements over Windows 7 and is also a lot more secure than Windows 7 (there are quite many viruses thay simply cannot be started on default Windows 8 installation). There are many reasons for you to choose Windows 8 unless you use some business critical application that requires Windows 7. I recommend you give Windows 8 a try.
This video from HP will help you -> http://www.youtube.com/watch?v=T1lXtOxFWbE
Changing between Desktop ("old Desktop or GUI)" and ModernUI is not very convenient for many people. In order to remedy some of the issues some customers face (line inconvenience between changing interfaces or other), Microsoft are going to release Microsoft Windows 8.1 -> free upgrade - new OS version this October, which brings back the Start button and the ability to use Desktop more.
Do not hesiate to post back if you need assistance !