Since you want to install the software for your HP printer, you need to be logged in with an administrator account. Because printer software requires modification to the operating system or it will create global changes to the platform, a user account with administrative privileges is required. You cannot use a standard account to install the software because it will not work.
Standard user accounts in Microsoft Windows can only install basic applications because simple programs like these will not modify part of the operating system. If you don’t have an administrator account, ask someone that has administrator account to install the printer software for you. Also, make sure you are installing the software on the right platform.
The driver for the HP Photosmart D7100 printer supports Windows XP, Windows Vista, Windows 7, Windows 8.x, and Windows 10 both 32-bit and 64-bit. If you need to download the software again, go to HP Photosmart D7100 Printer Series and download the driver. On the download page, select your correct operating system.