Removing and recreating EFI partition
EFI partition is simple vfat
. Make sure it's formatted as such.
Windows should write to it as long as the partition type is correct (use GPT with EF00
as the type code. If you have a hybrid MBR/GPT it's easier to remove the MBR and only keep the GPT if it's incorrect.)
If Windows was booting before, you should still have the bootstubs in your EFI partition. unless they've been wiped out somehow (say by a format of said partition or similar.) Are they there by chance?
It's interesting that you suddenly can't boot too; every distro has pretty much gotten coexistence down flat these days, and EFI made that much cleaner, so I'm interested in the above to try to find out what happened to get you into this state as it will surely help your recovery to know ;)
Care to share your current GPT + MBR part tables and such?
It would also help to know your EFI boot manager entries. If you can get into Linux, an easy way to see this is efibootmgr -v
.
Most likely, your old EFI boot entry still exists for the Windows boot, but is just set as a later priority. Linux installs tend to install some intermediary bootloader, such as grub/systemd-boot. You can typically access these and manage them from your EFI "setup" screen (on macs it's a different story, but that's an explanation for another day).
FYI, you can boot Linux kernels directly nowadays as well, as they contain an efi bootstub at the beginning of them since quite some time ago.
I'm guessing you had Windows installed and booting already, then installed Linux over top, yes?
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Kryštof Šádek
Updated on September 18, 2022Comments
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Kryštof Šádek almost 2 years
I've wanted dualboot Win 10 and CentOS, but TL;DR I ended up with non-booting notebook.
bootrec /scanOs
can't find Windows installation (it is still there though).Auto repair doesn't work, neither
bcdboot
orbootrec /fixboot/fixmbr/rebuildbcd
.So my question: is removing EFI partition completely (
diskpart
) and recreating it from the scratch (bcdboot
) worth a try?If it helps: Lenovo Thinkpad X260, SSD, GPT partition style, Win 10 Pro
(I would try to recreate the situation in VirtualBox, but available PC isn't capable of such thing.)
EDIT #1: I've removed the CentOS partition later on (tried to install Windows 10 there hoping for repaired boot manager but with no luck). So it's unformatted 30 GB space now
EDT #2: This is output from
diskpart
:DISKPART> list disk Disk ### Status Size Free Dyn Gpt -------- ----------- ------- ------- --- --- Disk 0 Online 238 GB 1024 KB * DISKPART> list partition Partition ### Type Size Offset ------------- ----------------- ------- ------- Partition 1 System 260 MB 1024 KB Partition 2 Reserved 16 MB 201 MB Partition 3 Unknown 1024 KB 277 MB Partition 4 Primary 206 GB 279 MB Partition 5 Primary 30 GB 206 GB Partition 6 Recovery 1000 MB 237 GB DISKPART> list vol Volume ### Ltr Label Fs Type Size Status Info ---------- --- ----------- ----- ---------- ------- --------- -------- Volume 0 C DISK NTFS Partition 206 GB Healthy Volume 1 RAW Partition 30 GB Healthy Volume 2 E SYSTEM FAT32 Partition 260 MB Healthy Hidden Volume 3 D WinRE_DRV NTFS Partition 1000 MB Healthy Hidden
EFI should be partition 1 / volume 2
EDIT #3: diskpart detail partition 1:
Type : c12a7328-f81f-11d2-ba4b-00a0c93ec93b Hidden : Yes Required: Yes Attrib : 0x0000000000000001 Offset in bytes: 1048576
EDIT #4: Boot menu:
#1 Windows boot manager (does nothing; black screen and takes me back here) #2 ATA HDD0: SanDisk SD8...001 (same as #1) #3 USB (my windows install media) #4 PCI LAN
UPDATE #1 The boot menu allows me to show Diagnostic splash screen where I noticed that
System BIOS shadowed
Video BIOS shadowed
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Pavlus almost 7 yearsCheck that you have single EFI volume and check partition flags, it must be flagged as EFI partition.
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Biswapriyo almost 7 yearsIf and only if you don't need any data from that HDD, you may go from scratch and full format HDD to install Windows.
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Rod Smith over 6 yearsDeleting and re-creating the EFI System Partition (ESP) is likely to make matters worse, not better; the ESP holds boot loaders, so deleting it will cause any boot loaders that are there, but that aren't being launched, to be lost. It's unclear what your "EDIT #4" boot menu is -- the EFI's built-in boot menu, a GRUB menu, or something else. A screen shot (digital photo) would help. My rEFInd boot manager on USB flash drive might help, at least as a temporary/emergency tool. Windows and CentOS recovery procedures will each be unique.
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Kryštof Šádek almost 7 yearsI probably should have mentioned that linux is no longer present (formated). So my current set of tools is Windows installation, so
cmd
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Kryštof Šádek almost 7 yearsAnd it isn't hybrid GPT+MBR, just GPT.
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trevorj almost 7 yearsWhat do you mean by formatted? Care to elaborate there? A listing of your partition table(s), verification of the filesystem on your EF00 type'd partition, as well as a listing there would help.
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Kryštof Šádek almost 7 yearsI mean I have deleted the partition with Linux.
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trevorj almost 7 yearsI meant what partitions did you delete? Was one of them the EFI partition?
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trevorj almost 7 yearsCan you get a GPT listing that includes partition types in the output?
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Kryštof Šádek almost 7 yearsNono just with Linux. Although it has it's own /boot partition. But the original from before (created by Windows) it's still presented. I've edited my question and added output from
diskpart
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trevorj almost 7 yearsYeah, thanks for that. I'd still want to see the partition listing with partition table type codes to verify that volume 2 is set to EF00.
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trevorj almost 7 yearsAlso, getting your efi boot entries would also greatly help, it's likely related.
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Kryštof Šádek almost 7 yearsMay I ask how can I do that?
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Kryštof Šádek almost 7 yearsYep I had windows and installed linux afterwards. But then I ended up with non working boot. No grub neither windows boot manager showed up. BIOS boot menu is showing Windows boot manager in the first place but it doesnt work. Then is listed SSD doing the same thing and afterwards USB, network..