Bootmgr missing no cd/DVD drive

I am not trying to be difficult. I cannot get the broken computer to read anything off of the usb and a lot of ur info is beyond my ken. I can only open f2 which says "cmos setup utility". Is there any other way to get my computer to read the usb ? I downloaded the tool but again the broken pc wont read it. I tried step 1 ,,, I cannot get to system restore or any other screen. I cant even access f12 which says it is boot options. sorry I don't understand some of what is required. I open the links and I cannot even do step 1. I download the tools to usb from a laptop but then cannot get the broken pc to read it. I feel so stupid that I can't even do the simplest task, what am I doing wrong?

There are other methods to Clear CMOS - 3 Ways to Clear the CMOS - Reset BIOS

Try tapping the Dell F12 key more vigorously every 2 seconds from the moment you press the power button. Once you get to the Boot Menu choose Dell Diagnostics to test your hardware. Then see if the flash stick is listed under USB, Removable or HD's - you may have to expand one of those listings to see the actual stick and choose it navigating with the up and down keys.

If this fails try tapping the F2 key, then in BIOS setup look for the USB stick again as described above.

If no stick shows up, download another ISO file to write to stick using UltraISO Software To Create Bootable USB Flash Drive which always works for me. Then try looking again in the boot Menus which you can access.

If this fails try all other USB ports. Are other USB devices working in them?

If nothing works, then move the HD to another PC to copy out your data, wipe the HD with Diskpart Clean Command which will force the Win7 installer to boot when the HD is moved back to the problem PC.

ok f12 will not work. f2 key brings up advanced bios features or bios security features. I do not see bios setup.

for the next step do I wipe the usb clean?

Those BIOS features should include tabbed menus which offer Boot order Priority, a setting to Reset to Defaults. Almost all BIOS do. How to Boot A Computer from CD or DVD - YouTube

Ultra tutorail shows how to Open the ISO file, Write Disk Image from Bootable tab, then click Format, then Write.

These operations require an attention to detail that misses nothing in reading these steps and tutorials.

Hi Ravenisls do you have a copy of your original windows 7 on a DVD disc. If you have, try to download image burn application this will make a image copy of your Windows 7 it will make a ISO image that you can use to make a USB bootable Windows 7.

i do not have dvd but optical drive is not reading anything anyway. I can only open setup and I changed boot order but then the message says operating system is missing. I have tried to make a usb from another desktop but 5 computers in the house and they all have different os. I cannot figure out how to find iso image to download to usb download tool. I have tried many different ways to make a dvd but i seem to be doing something wrong or missing some small detail........

Download the Win7 ISO for your licensed version, install Ultra ISO trial, on File tab Open ISO file from where you downloaded it, on Bootable tab select Write Disk Image, in window that opens confirm in Computer correct letter for flash stick, once you're absolutely sure of flash stick drive letter recheck it's showing in dropdown menu, then click Format, then Write.

Boot the flash stick using the one-time BIOS Boot menu key given on first screen, under USB, Removable, or HD's - you may have to expand a listing to see the actual stick and choose it to boot.

Let us know if this is enough to get it booted. Folllow the repair steps and report back each result.