Sometimes the windows boot files are stored on this partition.

The windows boot repair procedure will sort this out.

I vaguely seem to remember that windows needs a repair / restore (hidden) partition directly adjacent to its C: drive. I can't see anything like that in your screenshot. If anyone here knows more about that ... sorry, I don't use windows since more than 20 years.

The best source of information on what the microsoft reserved partition is would be the microsoft site. Links below. According to the links below, it is used only on UEFI/GPT systems. You don't have that but the computer is probably capable of it. I don't use windows so can't explain any of it. What I find interesting is that sda3 has the boot flag in your gparted image? If the links below are accurate, having a boot flag on that partition would be pointless. You might try changing the boot flag to sda4 with gparted. Linux systems don't use it. Otherwise try the windows repair tools.

https://answers.microsoft.com/en-us/...6-8c82d828631f

https://learn.microsoft.com/en-us/pr...799232(v=ws.10)

An MBR install such as your would originally have some windows boot code in the MBR and the rest on the system partition which would be what is referred to as C"\ in windows. Some previous versions of windows (7 to be specific) had a separate boot partition. Newer versions of windows have an EFI partition which also includes some boot files. You do not have an EFI install so that is not a concern.

Thank you all for the help and good advice. I haven't been able to get the windows 10 usb to boot up. I have about decided to pull the trigger on a full new install of Linux Mint 21.2, double my ram to 32gb and go to vm for windows.

Looking back on it, I think the computer came either with vista or windows 7 and was updated to windows 10. Seems that can cause some bios issues? Over the years I have added many linux applications from 3rd party repositories. Bottom line, it's probably time to have a clean start. All data is backed up on my nas so a few hours of transferring it over should put me back to the good.

Thanks again. You all have been very helpful.

How did you create the usb. I think you have to use windows media creator to put the iso onto the usb.

This system here was originally a windows 7 that was upgraded to windows 10, and now has windows 11 installed on it in dual boot with windows 10. It is a Hp AMD Phenom 9550 Quad-Core Processor system legacy system that came out before uefi and tpm became the standard.

Did you try setting the boot flag to sda4? What happened?

You could try the entry shown at the link below for windows 7. Since you have 10 but it is in Legacy mode, it should work. Change the set root line to (hd0,4). I would put this in your grub.cfg file and not update grub but just reboot to test. If it fails, just delete that entry in grub.cfg. If the windows boot files are there and were not lost or corrupted when you moved the partition, I would expect it to work.

https://technologytales.com/2010/11/...tu-grub2-menu/

Yes. Not sure it made any difference.

With bios setup to boot iaw 1.png (attached) I get the boot option screen 2.png which is normal. I can boot into linux but if selecting windows 10 results in black screen. Occasionally I get 3.png but none of the options work. The "Recovery" screen flickers and refreshes.

With bios setup to boot iaw 4.png (attached) I get 5.png. Selecting any of those diagnostics or setup utilities opens the Dell applications to check hardware.

I will work on this.

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I can't read the first image, the part highlighted in blue under settings.

Neither am I? Did you make the change? Did you use gparted? If you open gparted, highlight sda4 in the main window, right click on the highlighted partition and select Manage flags and check the box next to boot. If you did/do this, update grub? Does it show an entry for windows? Is it still sda3?

..............................

If this doesn't work with the boot flag at partition 3
AT the grub menu press e for edit and change the 4 to a 3, ctrl-x to boot.
If that doesn't work, set the boot flag on partition4 and use the entry as is and/or with a 3.

1 members found this post helpful.

The simplest method is the suggestion in post 26 above.
In a case where you want to simply test an entry, the next easiest method is to edit grub.cfg and save the change. If you do that, do NOT update grub. If you want a permanent entry, use the 40_custom file suggested in the link. Not much point in doing this until you know it works so go with the suggestion in post 26. This is a one time change, if you reboot to test again you need to use the 'e' key and make the change again.

After you changed the boot flag to sda4 and tried to boot windows, what happened? Black screen, BSOD, error messages? Details needed. If neither option works, mount the windows system partition (sda4) from your Linux and look for a BOOT or BCD directory and/or files. I don't know exactly which files are needed on a Legacy windows system. Depending upon what messages (if any) you get trying to boot windows, the boot files may be missing or corrupted.

Thank you both, again.

At the boot menu I press "e" and see this: (see attachment 1)

I edit the 3rd line to set root='hdo,4' then Ctrl+x and I get this: (see attachments 2 & 3)

Then have to force shut down computer.

BTW, in case it helps, at the menuentry line my /boot/grub/grub.cfg reads:

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows 10 (on /dev/sda3)' --class windows --class os $menuentry_id_option 'osprober-chain-08420730420721D4' {
insmod part_msdos
insmod ntfs
set root='hd0,msdos3'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos3 --hint-efi=hd0,msdos3 --hint-baremetal=ahci0,msdos3 08420730420721D4
else
search --no-floppy --fs-uuid --set=root 08420730420721D4
fi
parttool ${root} hidden-
drivemap -s (hd0) ${root}
chainloader +1

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How did you move the windows system partition, the one that is now sda4? Did you create sda4 and then move all the windows files to sda4? The UUID you show in the menuentry you posted for sda3 is: 08420730420721D4

Run the blkid command to get the UUID for sda4. If it is not the same, change it in the grub.cfg file and change the set root line to (hd0,4) and reboot to test.

The images you posted (2 and 3) are running memtest and that is not what you want obviously.

How did you move the windows system partition, the one that is now sda4? Did you create sda4 and then move all the windows files to sda4? The UUID you show in the menuentry you posted for sda3 is: 08420730420721D4
Run the blkid command to get the UUID for sda4. If it is not the same, change it in the grub.cfg file and change the set root line to (hd0,4) and reboot to test.

The images you posted ( 2 and 3) show you are booting into memtest and the uuid for that partition is a Linux UUID starting with c7d..... (hd0,4) should be a windows UUID. Check the output of blkid (or post here if you are not sure).