Old Optiplex Can't Find A Bootable Hard Drive

Don't Panic

One cause may be a dead CMOS battery and the BIOS reset to default.

When the following is done:

Running bcdboot does two things: it refreshes the boot files just in case, and more importantly, it forces the motherboard to write a brand-new UEFI NVRAM bookmark pointing straight to your Windows drive.

F2 and check the BIOS. If it's set to Legacy and Raid instead of AHCI and the date is somewhere in 2007, the battery is probably dead.

Window's 11 can run on legacy boot but it's a little risky and doesn't always work.

What to do.

1. Install a new battery

2. Create a Windows install bootable flash drive.

3. Open the Gemini app on your phone and tell it what is going on.

You are all set. Do what it tells you to do.

Good Luck

Gemini and I fixed the boot sector and BIOS settings once. I noticed the date problem and reset it but didn't' bother replacing the battery. In the old days we could just F1 and continue to boot. Those days oar over. After a fer weeks it happened again. I had to do it all over but this time I replaced the battery.

Ventoy Hint

I dropped a downloaded Win.iso onto Ventoy. I would not boot in standard mode. I had to use Wim-boot. It loads everything into memory and boots. 

Here is the entire process:

Windows Can't Find A Boot Drive

(This assumes Windows was installed as UEFI boot before the failure).

Boot to BIOS

(usually F2)

Check if set to:

Windows Boot Loader

UEFI

AHCI (Don't worry if changing from RAID. Change it. Win11 will handle the change)

Determine the OS drive letter and the volume number of the EFI partition

(Drive letter may not be the same as when the PC is booted).

Boot to Wininstall.iso from a flash drive. F12 launches boot selector in Dells.

At the first screen:

Shift + F10 for command prompt

diskpart

list disk

You see the list of disks.

If obvious say in diskpart.

If not, exit diskpart and check for the right disk.

dir

(Determine the disk letter)

You may need to access the drive and be sure it contains the Windows install.

Let's assume the drive is D

diskpart

list disk

select disk D

list volume

The EFI volume will not (usually) have a letter.

It must be given a letter to write to it.

It will have a size of 100MB-500MB and be FAT32

Let's assume the volume of the EFI is 3

In diskpart do this:

select volume 3

assign letter=S

exit

Exit is needed because the next commands are in command prompt

bcdboot D:\Windows /s S: /f UEFI

Fix Boot Sector

 

Commands:

bcdedit

bootrec /fixmbr

bootrec /fixboot (if you get error? type) bootsect /nt60 sys

now type bootrec /fixboot

diskpart

list disk

select disk 0 make sure its your windows drive

list volume (find system volume it will be fat32 hidden)

select volume 3  

(make sure its the fat32 volume and change number of volume to your number)

assign letter=n (Make sure your not using N: drive letter)

exit

n: (Change to your drive letter)

cd efi

cd Microsoft 

cd boot

attrib bcd -h -r -s

ren bcd bcd32.old

bootrec /rebuildbcd

type A

bcdboot c:\windows /s n: /f UEFI

Now boot to windows.

Commands:Commands: bcdedit bootrec /fixmbrCommands: bcdedit bootrec /fixmbr bootrec /fixboot (if you get error? type) bootsect /nt60 sys now type bootrec /fixboot diskpart list disk select disk 0 make sure its your windows drive list volume (find system volume it will be fat32 hidden) select volume 3 (make sure its the fat32 volume and change number of volume to your number) assign letter=n (Make sure your not using N: drive letter) exit n: (Change to your drive letter) cd efi cd Microsoft cd boot attrib bcd -h -r -s ren bcd bcd32.old bootrec /rebuildbcd type A bcdboot c:\windows /s n: /f UEFI Now boot to windows. bootrec /fixboot (if you get error? type) bootsect /nt60 sys now type bootrec /fixboot diskpart list disk select disk 0 make sure its your windows drive list volume (find system volume it will be fat32 hidden) select volume 3 (make sure its the fat32 volume and change number of volume to your number) assign letter=n (Make sure your not using N: drive letter) exit n: (Change to your drive letter) cd efi cd Microsoft cd boot attrib bcd -h -r -s ren bcd bcd32.old bootrec /rebuildbcd type A bcdboot c:\windows /s n: /f UEFI Now boot to windows. bcdedit bootrec /fixmbr bootrec /fixboot (if you get error? type) bootsect /nt60 sys now type bootrec /fixboot diskpart list disk select disk 0 make sure its your windows drive list volume (find system volume it will be fat32 hidden) select volume 3 (make sure its the fat32 volume and change number of volume to your number) assign letter=n (Make sure your not using N: drive letter) exit n: (Change to your drive letter) cd efi cd Microsoft cd boot attrib bcd -h -r -s ren bcd bcd32.old bootrec /rebuildbcd type A bcdboot c:\windows /s n: /f UEFI Now boot to windows.mmands:

bcdedit bootrec /fixmbr bootrec /fixboot (if you get error? type) bootsect /nt60 sys now type bootrec /fixboot diskpart list disk select disk 0 make sure its your windows drive list volume (find system volume it will be fat32 hidden) select volume 3 (make sure its the fat32 volume and change number of volume to your number) assign letter=n (Make sure your not using N: drive letter) exit n: (Change to your drive letter) cd efi cd Microsoft cd boot attrib bcd -h -r -s ren bcd bcd32.old bootrec /rebuildbcd type A bcdboot c:\windows /s n: /f UEFI Now boot to windows.

Create Windows System Repair Disk

When windows won't boot or you are caught in a "windows shut down incorrectly" loop, you will need a Windows 7 install disk or Windows 7 repair disk. Chances are good you can't find your install disk if you ever had one so creating a repair disk may be your only option. I think this is 32/64 bit specific so you need to use a matching windows machine. Start Menu and right click/properties on "computer" will tell you if your Windows is 32/64. On the non-booting machine, if it has 4GB RAM or more it is probably 64 bit.

To make the repair disk go to Start Menu and type "system repair disk" and the option should pop up. Burn the disk and use it. You need to be able to boot from the CD. If your system does not automatically boot from the CD (it probably will), try to bring up the boot menu by pressing the boot menu key. This varies by motherboard BIOS but some possibilities are "esc", F10, F12, F2. The bottom of the screen during boot should tell you but it may go by fast and make reading difficult.

I guess I should mention how if nothing brings up the boot menu you will need to enter the BIOS setup and change the boot order so the CD is listed first.

If you need to make an ISO do this:

Well, I know the others are trying to help but I am pretty sure none of these answers solved it because I was with the same problem as you. So here was what I found:

Steps:

1 - Open your temp folder through: Start + Run (type on the search programs and files box "run", or shortcut windows+d) + type %temp% on the Run box (it will open your temp folder);

2 - Go to the system repair disc tool (Yes, I know there is no disc on the drive): Start / All Programs / Maintenance / Create a System Repair Disc

3 - Once you click to create a disc you are going to receive a message "System repair disc could not be created. There is no media in the device.". It's ok, continue closing ONLY this message, the Create a system repair disc windows MUST still be open.

4 - Now you can see at the temp folder, you have a new file called "somesortofbignumber.iso" around 100 or 200 MB (if you can't see it press F5 to refresh the folder). But still, you can't move, or copy, or anything the file because the system says it is in use. That is your ISO file, you just can't do anything with it yet. So, in this part you have to use a program that lets you manage these kind of files. I used one called Unlocker.

5 - After you installed Unlocker the only thing you have to do is: Right click "somesortofbignumber.iso" + select Unlocker + select the option "Copy" and the destination folder (remember if you want to rename the file don't forget the ".iso" ending).

After that you can search for a USB tool solution from a ISO file.

It worked very well for me, good luck.