Hello Everyone,
I hope someone can help me.
I have an HP G6 notebook with 6Gig of ram and a 500Gig HD. I started with Windows 8. I installed Point Linux as a second OS on a second partition. Installed Grub boot on a thumb drive. Worked great. About 6 months later Windows update installed Windows 8.1 all on it’s own. I tried booting into Linux and it still worked. I didn’t like 8.1 though. Along comes Windows 10 so I install. Big mistake, so I tried to roll back to Windows 8 without any luck. I am locked into Windows 10. Put thumb drive in to boot to Linux and it starts to load but stalls on this screen:
[ 3.046224] [Firmware Bug]: cpu 1, try to use APIC500 (LTV offset 0) for vector 0x10400, but the register is already in use for vector 0xf9 on another cpu
[ 3.046269] [Firmware Bug]; cpu 1, IBS interrupt offset 0 not available (MSRC001103A=0000000000000100)
[ 3.046308] Failed to setup IBS, -22
Loading, please wait…
After waiting 30 min. I tried to reboot with ctrl, alt delete. Got the same results, Loading, please wait… I did another reboot and pulled the thumb drive out to boot to Windows and got this screen: No bootable device – insert boot disk and press any key
I put the thumb drive back in and when Grub came up I scrolled down to load Windows and got this message: error: no such device 4EE64F65E64F4C81.
error: no such partition.
Press any key to continue…
So, I reboot and scroll down to Windows Recovery and it says to insert Windows installation disc and restart the computer. It also says:
File: \Boot\BCD
Status: 0x000000e
Info: The boot configuration for your computer is missing or it contains errors.
I have no installation disc for Windows 8. I want to use Linux but I also have to have Windows for other things I do. Can someone help with this problem?

Assuming you have UEFI disabled, a live disk (such as partedmagic) will see what partitions you have left and you might be able to copy the data.

You could try a recent version of supergrub (another 'live disk' event needed to be installed to a boot media) to see if that will boot any existing grub config but that configuration might be confined to "windows.old", or where win10 put win8.

If you want Windows back (cough, spit) you might need to visit "validation" stuff you got when you bought the pc and phone them after downloading the iso (on GNU/Linux machine?) for win 10/8 and installing to said pc via cd/dvd, in order to validate.

Fred.

Do some google, I had a failed W10 upgrade that didn't boot after rollback, the main OS partition was no longer marked as a NTFS partition. I had done a complete image with dd prior to upgrading, and restored that image to fix, but I recall seeing some information about using windows command line program DISKPART to fix the problem.

Did dd copy the image/drive without getting any errors or did you set it to ignore errors?
And what did you dd?- just "/boot" to a pendrive or what exactly?
If you change a boot 'setup' you need to tell grub about it, "update-grub" to change the grub.cfg file. All this assumes that win10 works with grub.

You could, of course, try to recover data before proceeding further, if important stuff is on there.

ops, miss-quoted.

however, the old grub pendrive will not work because it does not know you have put win10 on the pc.

Fred.

Booted a live Fedora usb and copied the entire hard drive (dd if=/dev/sda of=...). When I had to restore, I just rewrote the entire hard drive (dd if=... of=/dev/sda)

Doug G / dam50 ?,

either way, if you did the dd to save the drive before upgrading to win10 (good) then that might still lead to problems if there were errors in the dd process. If you set 'noerror' then it will carry on regardless but if you did not it will stop. In either case you will not get what you expected.

In order for the pendrive of grub to continue to work it needs to be made aware of any changes or it is likely to revert to some kind of rescue mode.

Fred.

why would you expect errors in dd? I've only seen errors occur with dd and hard drive imaging when there was a hardware problem with one of the drives.

Well, have you successfully used dd to copy and restore Windows systems before?

I ask because Win systems ( I think) are likely to have 'binary blobs' on them which are designed to be unreadable and might result in an error.

Cloning a device is perhaps not as precise.

Fred.

Often. For many years, from win 98 systems to win 10 systems. What kind of "binary blob" are you thinking of? Windows systems don't have any such thing. Maybe old hardware copy-protection schemes could cause dd problems, they will on floppies/optical media, but I haven't ever seen anything similar on a hard drive. That's not to say such things don't exist.

In any case I wouldn't use NOERROR, if my image is going to be corrupted due to a bad sector I'd rather know before I save the image and then try to restore sometime later, ending up with hard-to-isolate problems in the restored system.

Thank you everyone for your replies. I am now back to Windows 8 and Linux dual boot. This is a great community, think I will like it here.