Can't Reset to Factory Settings

Hello, I have a HP Envy x2, which I purchased refurbished with Windows 8 pre-installed. After I upgraded to Windows 8.1, I starter to notice many problems such as; the tablet wouldn't start all the time, the secure boot was disabled (but I fixed that), the app store doesn't work all the time, and Windows Update can't check for updates. The HP did not come with a recovery thumb drive or DVD. And I...