DO NOT DELTE DellUtility Partition !
Do not DELTE EFI System Partion !
The EFI System partition is a partition on a data storage device that is used by machines that adhere to the Extensible Firmware Interface. It contains the boot loader programs for all operating systems installed (in other partitions) on the device, device driver files (used by the firmware at boot time) for other devices, and system utility programs that are intended to be run before an operating system is booted
To restore your machine back to factory default
1 Back up any important files from your computer. Since the utility partition will restore the computer to its state when you first purchased the computer, any files you added since then will be lost. Either move your files to a portable hard drive or burn them to a CD or DVD.
To connect the hard drive, insert one end of a USB cable into your hard drive and the other end into a USB port on your computer. Then drag or copy any files from your computer to the hard drive. To burn a CD or DVD, insert the blank disc. A window will pop up asking what you wish to do with the disc. Select "Burn files to a CD/DVD" and follow to prompts to burn the disc.
2 Unplug any unnecessary accessories. This includes any printers, external hard drives or other USB devices.
3 Restart your computer. Select "Start," "Shut Down," then "Restart" for Dell computers running Windows XP or earlier. Windows Vista and Windows 7 users can click the Microsoft logo on the taskbar, click the arrow next to the "Shut Down" button and then click "Restart."
4 Press and release the "Ctrl" and "F11" buttons when the Dell BIOS screen appears
. The BIOS screen is the screen with the Dell logo that first appears when your computer starts. This will open the utility partition menu.
5 Select "Restore" when the Dell PC Restore menu appears. This will start the restoration process. Follow the prompts that appear until the process is complete. This will restore the system to include the settings and software included when you first purchased the computer.