Bootmgr is missing, press ctrl+alt+dlt to restart

Make sure the connections to the hard drive and the optical are good and tight.

Did you change the boot order to 1st for the dvd/cd drive in the bios ?

Or you can use the 1 time function key to bring up the boot order, it will show you which key to push at the bottom of the screen during initial bootup. F1, F2, Esc, Del etc.

Hi Nitaius ,

Do you have a second PC to try to create a bootable USB flash drive with Windows 7 Installation Files ? Link to USB Windows 7 Installation Key Drive - Create I believe if you press ESC on the ASUS splash screen you should get the Quick Boot Options menu choose your DVD drive and it should load the DVD.

Boot into BIOS setup by tapping the key given for it on first boot screen. If you'd fill in your System Specs we can tell you exactly how it's done. Is the HD detected under storage devices? Now in BIOS boot order is it set to boot first? If not check cables and connections.

If so work through these steps for Troubleshooting Windows 7 Failure to Start.

Failure to boot a disk is 95% of the time user failure. Make sure you're following the steps How to Boot A Computer from CD or DVD - YouTube. The Win7 ISO for your licensed version is in Step 5 of first tutorial I linked, along with tool to burn to DVD or write to flash stick.

Once you trigger the DVD or flash strick to boot, does it prompt to "Press any key to boot disk?"

Might want to check this link Bootmgr is missing - Fix