Efi Dualboot windows 7 OpenSuse 12.3

Hello everybody,

I have an hp computer 64 bits with efi boot and Windows 7. I have installed OpenSuse successfully in a 300 GB partition. After installed OpenSuse, when I tried to access to Windows partition, I become following error message


I have read in internet that one can access to windows partition through the boot by pressing F9 or F12. But unfortunately I cannot, the computer said that no boot disk is detected.


I am not an expertise and I don´t know how to solve this problem. Any help?

Thanks in advance for your help

I don’t know whether I can help. I have Win8 and opensuse in efi boot, but I don’t know about Win7.

We are going to need more information.

(a) provide the output from

# efibootmgr -v

That needs to be run in a terminal window as root. Please use code tags around the output. Clicking the “#” button in the forum edit window will do that. If you paste in the output, then select what you just pasted in with the mouse and click that “#”.

(b) provide the output from

# parted -l

Also do as root from a terminal window, and also use code tags.

The first of those commands gives us information about your efi setup. The second gives us the disk partitioning information.

I think your only choice is to enter the PC UEFI setup and select Windows to boot. Its due to these oddities that I have stuck with MBR formatted boot disks where the grub 2 menu still works, including with Windows 8.1.

Thank You,

I suspect he overwrote the EFI partition (Boot and Microsoft folders included) … :\

x1-6-80-c1-6e-f3-6a-19:~ # efibootmgr -v
BootCurrent: 0003
Timeout: 2 seconds
BootOrder: 0003,0000,0001,0002,0004,0005,0006,0007,0008
Boot0000* Windows Boot Manager  HD(1,800,32000,de5dc3b9-3d9e-4546-aa04-dc714f212851)File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.}...o................
Boot0001* USB Floppy/CD Vendor(b6fef66f-1495-4584-a836-3492d1984a8d,0500000001)AMBO
Boot0002* USB Hard Drive        Vendor(b6fef66f-1495-4584-a836-3492d1984a8d,0200000001)AMBO
Boot0003* opensuse      HD(5,4d7ba800,52000,0d5fea4c-2b7d-4736-9ae9-b0a88fafd78f)File(\EFI\opensuse\grubx64.efi)
Boot0004* ATAPI CD-ROM Drive    Vendor(b6fef66f-1495-4584-a836-3492d1984a8d,0300000001)AMBO
Boot0005* CD/DVD Drive  BIOS(3,0,00)AMGOAMNO........o.h.p. . . . . . . .C.D.D.V.D.W. .S.H.-.2.1.6.A.L.N....................A...........................>..Gd-.;.A..MQ..L.8.R.H.L.G.6.C.D.0.4.H.3.A.2. . . . . . ......AMBO
Boot0006* USB Floppy/CD Vendor(b6fef66f-1495-4584-a836-3492d1984a8d,0500000000)AMBO                     
Boot0007* Hard Drive    BIOS(2,0,00)AMGOAMNO........o.H.i.t.a.c.h.i. .H.D.S.>..Gd-.;.A..MQ..L. . . . . . .S.M.5.E.1.2.V.5.Y.1.R.J.U.9......AMBO
Boot0008* Realtek PXE B04 D00   BIOS(6,0,00)AMBO

x1-6-80-c1-6e-f3-6a-19:~ # parted -l
Model: ATA Hitachi HDS72101 (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt_sync_mbr

Number  Start   End     Size    File system     Name                          Flags
 1      1049kB  106MB   105MB   fat32           EFI system partition          boot
 2      106MB   240MB   134MB                   Microsoft reserved partition  msftres
 3      240MB   666GB   665GB   ntfs            Basic data partition
 5      666GB   666GB   172MB   fat16           primary                       boot
 6      666GB   668GB   2155MB  linux-swap(v1)  primary
 7      668GB   689GB   21.5GB  ext4            primary
 8      689GB   988GB   298GB   ext4            primary
 4      988GB   1000GB  12.5GB  ntfs            Basic data partition

I have quoted just a small part of your output.

If I am reading that correctly, then you are using two EFI partitions, probably “/dev/sda1” used for booting Windows and “/dev/sda5” for booting opensuse.

That did not work for me with Windows 8, but has since been fixed. But possibly, Windows7 is a bit more fussy.

I think you should be able to boot Windows, after running opensuse, by using the command:

# efibootmgr -n 0

That tells your BIOS to boot from entry 0, which is Windows, on the next boot. After that, it will go back to booting opensuse until you repeat that command.

Maybe you can try that. If it doesn’t work, then there is something more seriously wrong with your Windows installation. If it does work, we can probably find ways to set it up so you won’t have to do that every time.

I’ll await the results of that test.

After using the command

I restart my computer and start to boot windows, the starting windows window appears. After that unfortunately it comes back to the opensuse start menu.

Unfortunately, that indicates that there is something broken in your Windows installation. You’ll need to do a Window repair. And I’m not a Windows expert, so I don’t know how to advise you on that.

You could perhaps try

# efibootmgr -n 7

That boots directly from the disk, rather than the Windows nvram entry. My guess is that this won’t work either, but there’s an outside chance that Windows tries to do some repairing when you boot that way.

x1-6-80-c1-6e-f3-6a-19:~ # parted -l
Model: ATA Hitachi HDS72101 (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt_sync_mbr

Number  Start   End     Size    File system     Name                          Flags
 1      1049kB  106MB   105MB   fat32           EFI system partition          boot
 2      106MB   240MB   134MB                   Microsoft reserved partition  msftres
 3      240MB   666GB   665GB   ntfs            Basic data partition
 5      666GB   666GB   172MB   fat16           primary                       boot
 6      666GB   668GB   2155MB  linux-swap(v1)  primary
 7      668GB   689GB   21.5GB  ext4            primary
 8      689GB   988GB   298GB   ext4            primary
 4      988GB   1000GB  12.5GB  ntfs            Basic data partition

Your second ESP/EFI partition is FAT16, and that is where Grub2 is installed and where you are booting from, if I understand things correctly. Windows would never create that partition. Windows (8 in particular, and if memory serves me right, that goes for W7 and Vista as well) doesn’t like anything but FAT32 when it comes to ESP partitions. That’s the first thing you need to fix if you want Windows to go with you. That may even be all you need to get things going.

Boot from an openSUSE live DVD and start gparted. Point it to your second ESP partition and convert it from FAT16 to FAT32. (You may even be able to do it from inside your already installed openSUSE, but you will need to dismount the ESP partition prior to converting its file system and that may pose a problem. I am a little unsure, but I don’t think you will need the ESP partition once booted except for maintenance and modifications. Which also means you can safely discard it after booting. The mount point is /EFI).

If the file system conversion doesn’t do what you need, you can do as nrickert said, and try to make W7 fix the booting problems for you. MS says how to do that here: Use the Bootrec.exe tool in the Windows Recovery Environment to troubleshoot and repair startup issues in Windows. (Short recap if link disappears in the future)

  • Boot from Windows installation disk:
  • Execute Startup Repair
    in the System Recovery Options.

If that isn’t enough:

  • Boot from Windows installation disk
  • Select environment (country, keyboard etc.) appropriate for you, then click Next
  • Click Repair your computer
  • Select OS, click Next
  • In System Recovery Options
    select Command Prompt - Type bootrec.exe
    and press the <enter> key.


The EFI partition is normally mounted at “/boot/efi”. You are right, that it is not needed after booting. Actually, it is not needed during booting either. It is only needed when grub or grub.cfg is being updated.

I’m not sure that the FAT16 or FAT32 actually matters. Windows uses FAT32, but it seems able to read the FAT16 EFI partition on my second disk. Okay, that’s Win8, not Win7.

Reformatting to FAT16 might cause problems if it changes the UUID of the partition. There’s a reference to the UUID in “grub.cfg”. There’s a reference to the GUID of the partition (from the partition table) in NVRAM, and I’m not sure if gparted would change that on a reformat.

**@**valentz: Stop! Read this before you continue according to my instructions!

I am truly embarrased! Here are several mistakes on my part.

I stand corrected. My mounting of the ESP partition under /EFI remains from my previous testing.

I must admit I haven’t tested that myself, but according to Booting from GPT (the maker of gdisk): “Windows 7 insists that its ESP use the FAT32 filesystem. If a disk has a FAT16 ESP, Windows will try to create a new FAT32 ESP. If it can do so, installation will proceed to a point but then fail. Unfortunately, many Linux installers create FAT16 ESPs by default, so you may need to back it up, create a new FAT32 filesystem, and restore the files if you install Linux first.”.

But, ok, he is talking about installing W7. Not booting afterwards, like we have here. That may be the difference needed in this case, so you may be right and my suggestion may not be needed. However, doing disk/partition checks from within W7 using MS tools is not a good approach when W7’s surroundings are out-of-spec, so to say.

You are absolutely right. I made a test on my own computer. Worse, gparted will not CONVERT file systems and keep existing data as Partition Magic (which I recommend against using for other reasons) could do. Since I have found gparted otherwise to be equal to or superseed Partition Magic, I didn’t mentally note the full meaning of the word FORMAT when selecting file system in gparted until you wrote the word - and that made me jump in my chair. gparted cannot convert file systems - only reformat. That is data destructive - which means you need to back up before reformatting to FAT32 AND gparted will set a new UUID! I have confirmed the UUID part now. gparted allows you to set a new UUID by itself, but only a random one - it will not allow you to edit the value to your own taste.

I also did inspect the partitions made by gparted during my test by using gdisk, and some of the status-es given confuses me. I need to read up on the very tiny details of MBR/GPT/FAT/UUID and how the things are held together as a whole, to digest that. If gdisk is right, this seems to involve more than just the layouts of the MBR table/protective MBR table and GPT table. It appears to involve how that works within each partition as well as the full, physical storage medium. I didn’t think the two latter mattered, but gdisk seem to indicate otherwise. I’ll be back with more info on that.

Again, I’m sorry for my mistakes.


We learn by experience, which includes trying stuff and making mistakes.

I’m still learning, which implies that I still make mistakes.

To slightly change topics, the really big problem that I see for GPT partitioned disks, is the sector size.

I have a 1T disk. According to “gdisk” it has a physical sector size of 4K and a logical sector size of 512 bytes. The GPT partition table is based on that 512 byte logical sector size.

If I take that same disk out of my computer, and mount in a USB connected hard drive enclosure, then it shows as having a logical sector size of 4K. This means that the partition table is incompatible between those two ways of accessing the disk. This was a terrible design decision. The partition table structure should have been based on the more reliable physical sector size instead of the unreliable logical sector size. I see problems down the road because of this.

If you do it with two ESPs on the same hard disk, you will damage Windows bootloader beyond repair. You should delete (change type of) partition created by openSUSE to something else so it is not treated as ESP by Windows. Then you could use Windows recovery.

Are you sure it is GPT that is doing that to you? Isn’t Advanced Format (or, rather, Advanced Format 512e, to be precise) the real culprit (Advanced Format - Wikipedia, the free encyclopedia) - and gdisk/GPT just reporting what the disk says? If connecting through USB does hide the effect of Advanced Format, I would think Advanced Format would hamper more than GPT partitioning alone?


If that is so, that is another reason for banning more than one ESP in a dual-boot setup with Windows. I’ve seen many posts around in this forum from people preferring otherwise…


It may be the advanced format. Still, the disk looks different via USB than when installed as a hard drive.

I originally partitioned as a USB drive, using “gdisk”. Fortunately, the only partition created was the protective partition used to simulate an MBR. When looked at, with the disk properly mounted as a hard drive, the protective partition covers only 1/8 of the drive capacity. When orginally looked at via a USB enclosure, it was the whole drive.

Puzzling. What is the make and model of your harddisk?


Seagate ST1000DM003-9YN1

openSUSE will default to reusing existing ESP

I’ve seen many posts around in this forum from people preferring otherwise…

On the same disk? Or on different disks?

Anyway, you will not be aware of this issue until this is too late - i.e. when you need to recover your Windows boot manager. Few people need to ever do it.

Yes, that disk has Seagate’s variant of Advanced Format; they (did?) call it SmartAlign. BTW I found they announced a firmware upgrade for it: Barracuda (1TB/disk platform) Firmware Update. There’s no date on the page though, so I don’t know how old it is. One of the documentation pages linked from that page, displays a ReadMe-file dated March 2008 (this date is why I said “(did?)” above, SmartAlign may already be outdated, replaced or improved upon. I haven’t checked that now) - but again, I don’t know if that is just an example or a part of the true file being displayed.

But what you describe is still puzzling. I’ll continue to read up on partitioning and have that in mind too. It could be that the various disk-manufacturers ways of implementing Advanced Format may be a factor to take into account (they all seem to have different names for it, but that may just be marketing, though). Maybe some answers can be found. I’ll be back in another thread when I have found anything of interest.