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Can I re-enable Secure Boot, Fast Start-up, or Bitlocker on Win10 on Dual boot (Grub default) Ubuntu18.4 system?

Unable to mount Windows (NTFS) filesystem due to hibernationUse (Windows) BitLocker-encrypted drive on Ubuntu 14.04 LTSIs re-enabling Secure Boot in UEFI secure?Dual Boot with Windows 8 UEFI - Ubuntu/GRUB Being BypassedHow to enable Secure Boot without issue?Dual booting Win10/Ubuntu 15.04 starts in grub bashdual-boot with secure boot: invalid signaturesecure boot issue : win10 & ubuntu16.04No Grub, no boot after accidental “Secure boot enable”; dual bootI have dual-boot Ubuntu and Win10, what happens if i reinstall Win?Dual boot Ubuntu 17 with windows 10 - Grub doesn't startChainload from windows boot manager to Grub with Secure Boot enabledInstall Ubuntu 16.04 on HDD of a computer with Secure Boot that has Win10 on SSD

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

0

Can I re-enable Secure Boot, Fast Start-up, or Bitlocker on Win10 on a Dell Inspiron 15 3567 Dual boot (Grub default) Ubuntu18.4 Windows10 system? What are risks or implications.

dual-boot windows-10 secure-boot

share|improve this question

edited Apr 13 at 22:08

mako34

asked Apr 13 at 15:32

mako34mako34

12

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Welcome to Ask Ubuntu. This is a question answer site. Please see site help for how to ask questions in this site. Please ask one question at a time.
  
  – user68186
  Apr 13 at 16:29
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  "peppermint9" off topic.
  
  – Rinzwind
  Apr 13 at 17:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If you think the answer is correct (the problem is solved) then put the green check mark (✔️) on the left margin of the answer. This will help others.
  
  – user68186
  Apr 13 at 22:02
  

  
  
  
  

add a comment | 

0

Can I re-enable Secure Boot, Fast Start-up, or Bitlocker on Win10 on a Dell Inspiron 15 3567 Dual boot (Grub default) Ubuntu18.4 Windows10 system? What are risks or implications.

dual-boot windows-10 secure-boot

share|improve this question

edited Apr 13 at 22:08

mako34

asked Apr 13 at 15:32

mako34mako34

12

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Welcome to Ask Ubuntu. This is a question answer site. Please see site help for how to ask questions in this site. Please ask one question at a time.
  
  – user68186
  Apr 13 at 16:29
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  "peppermint9" off topic.
  
  – Rinzwind
  Apr 13 at 17:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If you think the answer is correct (the problem is solved) then put the green check mark (✔️) on the left margin of the answer. This will help others.
  
  – user68186
  Apr 13 at 22:02
  

  
  
  
  

add a comment | 

Can I re-enable Secure Boot, Fast Start-up, or Bitlocker on Win10 on a Dell Inspiron 15 3567 Dual boot (Grub default) Ubuntu18.4 Windows10 system? What are risks or implications.

dual-boot windows-10 secure-boot

share|improve this question

edited Apr 13 at 22:08

mako34

asked Apr 13 at 15:32

mako34mako34

12

share|improve this question

edited Apr 13 at 22:08

mako34

asked Apr 13 at 15:32

mako34mako34

12

share|improve this question

edited Apr 13 at 22:08

mako34

asked Apr 13 at 15:32

mako34mako34

12

asked Apr 13 at 15:32

mako34mako34

12

asked Apr 13 at 15:32

mako34mako34

12

1 Answer
1

active

oldest

votes

0

Secure Boot

1. Ubuntu installs differently when secure boot is disabled.

When Ubuntu is installed in the UEFI mode with secure boot disabled, it installs EFIubuntugrubx64.efi.

When Ubuntu is installed in the UEFI mode with secure boot enabled, it installs EFIubuntushimx64.efi.

If you enable secure boot after installing Ubuntu, the Ubuntu will not not boot if the shimx64.efi does not exist.

The difference between shimx64.efi and grubx64.efi is that shimx64 is the actual Microsoft signed binary that works with Secure Boot enabled while grubx64 is the normal grub binary (Not signed).

2. Some third party device drivers can only be installed when secure boot is disabled.

The third party device drivers may not load and thus, some specific devices will not work.

See Is re-enabling Secure Boot in UEFI secure? for more.

Fast Start-up

Fast Start-Up or fast-boot can mean two things.

I assume this is the option in Windows 10.

This is not the UEFI option that skips the boot setup and boot device select menu when the computer boots.

Fast Start-up does not shut down Windows properly, and puts it in a hibernate state when Windows is shut down. This means all the partitions that are accessible by Windows (C:, D:, etc) are not properly shut down. Ubuntu will not be able access these drives properly in this state. In particular, you will not be able write files, including copy, move, etc., to these partitions when you use Ubuntu. This will be an issue if you have a common partition that you share between Windows and Ubuntu.

See Unable to mount Windows (NTFS) filesystem due to hibernation this answer for more explanation.

Bitlocker

Enabling Bitlocker in Windows will also make the Windows partition inaccessible from Ubuntu.

There may be ways to get around it. See Use (Windows) BitLocker-encrypted drive on Ubuntu 14.04 LTS

Disclaimer: I have not tried any of these things. So, there may be other consequences of enabling Secure Boot, Fast Start-up, and Bitlocker I am unaware of. Use at your own risk.

share|improve this answer

edited Apr 14 at 1:25

answered Apr 13 at 16:49

user68186user68186

17.2k85074

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  As long as GRUB loads or Windows does that's OK cause I can just reenter BIOS and shut off Sure Boot. The question is, does Windows try to interrogate GRUB for "integrity" (which I suppose it can't), or does it just ignore it to analyze the Windows boot (or is that bypassed by GRUB?)
  
  – mako34
  Apr 13 at 21:48
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Are you saying if you install Ubuntu with SB OFF,then it can't really be turned back on since it wasn't installed under proper SB protocols? As I understand it, only problems are with non-standard proprietary drivers so Ubuntu could have problems but Windows should be fine. Fast Start-Up obviously is unnecessary and risky; and Bitlocker scared me from first contact (ship computer with it enabled, where just booting up in Safe Mode can trigger a lock-out??), but I am in an insane threat environment & likely target, so would like Secure Boot, if possible, if it can give any additional protection
  
  – mako34
  Apr 13 at 22:04
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  An install with secure boot disabled will install the unsigned versions of the bootloader grubx64.efi. Turning secure boot on will then prevent grubx64.efi from booting, and there is no shimx64 either. That's why I like to install with secure boot on, then turn it off if necessary to install third party drivers. The system would then boot with secure boot in either state.
  
  – ubfan1
  Apr 14 at 1:18
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @ubfan1 Thanks! I edited the text to make it clearer.
  
  – user68186
  Apr 14 at 1:27
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Oh God, so it was stupid to install with SB Off, Ubuntu could say "dual install with SB on but then shut it off if there are boot problems!!" Can I convert grubx64 to shimx64 or delete it and load the latter? Can you elucidate on SB action with shimx64 - does it actually examine (integrity) the GRUB boot at all, or just ignore it; does it ignore the Windows boot sector (in which case viruses too would be bypassed) and go directly to Win startup?
  
  – mako34
  Apr 14 at 2:41
  

  
  
  
  

 | 
show 3 more comments

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0

Secure Boot

1. Ubuntu installs differently when secure boot is disabled.

When Ubuntu is installed in the UEFI mode with secure boot disabled, it installs EFIubuntugrubx64.efi.

When Ubuntu is installed in the UEFI mode with secure boot enabled, it installs EFIubuntushimx64.efi.

If you enable secure boot after installing Ubuntu, the Ubuntu will not not boot if the shimx64.efi does not exist.

The difference between shimx64.efi and grubx64.efi is that shimx64 is the actual Microsoft signed binary that works with Secure Boot enabled while grubx64 is the normal grub binary (Not signed).

2. Some third party device drivers can only be installed when secure boot is disabled.

The third party device drivers may not load and thus, some specific devices will not work.

See Is re-enabling Secure Boot in UEFI secure? for more.

Fast Start-up

Fast Start-Up or fast-boot can mean two things.

I assume this is the option in Windows 10.

This is not the UEFI option that skips the boot setup and boot device select menu when the computer boots.

Fast Start-up does not shut down Windows properly, and puts it in a hibernate state when Windows is shut down. This means all the partitions that are accessible by Windows (C:, D:, etc) are not properly shut down. Ubuntu will not be able access these drives properly in this state. In particular, you will not be able write files, including copy, move, etc., to these partitions when you use Ubuntu. This will be an issue if you have a common partition that you share between Windows and Ubuntu.

See Unable to mount Windows (NTFS) filesystem due to hibernation this answer for more explanation.

Bitlocker

Enabling Bitlocker in Windows will also make the Windows partition inaccessible from Ubuntu.

There may be ways to get around it. See Use (Windows) BitLocker-encrypted drive on Ubuntu 14.04 LTS

Disclaimer: I have not tried any of these things. So, there may be other consequences of enabling Secure Boot, Fast Start-up, and Bitlocker I am unaware of. Use at your own risk.

share|improve this answer

edited Apr 14 at 1:25

answered Apr 13 at 16:49

user68186user68186

17.2k85074

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  As long as GRUB loads or Windows does that's OK cause I can just reenter BIOS and shut off Sure Boot. The question is, does Windows try to interrogate GRUB for "integrity" (which I suppose it can't), or does it just ignore it to analyze the Windows boot (or is that bypassed by GRUB?)
  
  – mako34
  Apr 13 at 21:48
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Are you saying if you install Ubuntu with SB OFF,then it can't really be turned back on since it wasn't installed under proper SB protocols? As I understand it, only problems are with non-standard proprietary drivers so Ubuntu could have problems but Windows should be fine. Fast Start-Up obviously is unnecessary and risky; and Bitlocker scared me from first contact (ship computer with it enabled, where just booting up in Safe Mode can trigger a lock-out??), but I am in an insane threat environment & likely target, so would like Secure Boot, if possible, if it can give any additional protection
  
  – mako34
  Apr 13 at 22:04
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  An install with secure boot disabled will install the unsigned versions of the bootloader grubx64.efi. Turning secure boot on will then prevent grubx64.efi from booting, and there is no shimx64 either. That's why I like to install with secure boot on, then turn it off if necessary to install third party drivers. The system would then boot with secure boot in either state.
  
  – ubfan1
  Apr 14 at 1:18
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @ubfan1 Thanks! I edited the text to make it clearer.
  
  – user68186
  Apr 14 at 1:27
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Oh God, so it was stupid to install with SB Off, Ubuntu could say "dual install with SB on but then shut it off if there are boot problems!!" Can I convert grubx64 to shimx64 or delete it and load the latter? Can you elucidate on SB action with shimx64 - does it actually examine (integrity) the GRUB boot at all, or just ignore it; does it ignore the Windows boot sector (in which case viruses too would be bypassed) and go directly to Win startup?
  
  – mako34
  Apr 14 at 2:41
  

  
  
  
  

 | 
show 3 more comments

0

Secure Boot

1. Ubuntu installs differently when secure boot is disabled.

When Ubuntu is installed in the UEFI mode with secure boot disabled, it installs EFIubuntugrubx64.efi.

When Ubuntu is installed in the UEFI mode with secure boot enabled, it installs EFIubuntushimx64.efi.

If you enable secure boot after installing Ubuntu, the Ubuntu will not not boot if the shimx64.efi does not exist.

The difference between shimx64.efi and grubx64.efi is that shimx64 is the actual Microsoft signed binary that works with Secure Boot enabled while grubx64 is the normal grub binary (Not signed).

2. Some third party device drivers can only be installed when secure boot is disabled.

The third party device drivers may not load and thus, some specific devices will not work.

See Is re-enabling Secure Boot in UEFI secure? for more.

Fast Start-up

Fast Start-Up or fast-boot can mean two things.

I assume this is the option in Windows 10.

This is not the UEFI option that skips the boot setup and boot device select menu when the computer boots.

Fast Start-up does not shut down Windows properly, and puts it in a hibernate state when Windows is shut down. This means all the partitions that are accessible by Windows (C:, D:, etc) are not properly shut down. Ubuntu will not be able access these drives properly in this state. In particular, you will not be able write files, including copy, move, etc., to these partitions when you use Ubuntu. This will be an issue if you have a common partition that you share between Windows and Ubuntu.

See Unable to mount Windows (NTFS) filesystem due to hibernation this answer for more explanation.

Bitlocker

Enabling Bitlocker in Windows will also make the Windows partition inaccessible from Ubuntu.

There may be ways to get around it. See Use (Windows) BitLocker-encrypted drive on Ubuntu 14.04 LTS

Disclaimer: I have not tried any of these things. So, there may be other consequences of enabling Secure Boot, Fast Start-up, and Bitlocker I am unaware of. Use at your own risk.

share|improve this answer

edited Apr 14 at 1:25

answered Apr 13 at 16:49

user68186user68186

17.2k85074

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  As long as GRUB loads or Windows does that's OK cause I can just reenter BIOS and shut off Sure Boot. The question is, does Windows try to interrogate GRUB for "integrity" (which I suppose it can't), or does it just ignore it to analyze the Windows boot (or is that bypassed by GRUB?)
  
  – mako34
  Apr 13 at 21:48
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Are you saying if you install Ubuntu with SB OFF,then it can't really be turned back on since it wasn't installed under proper SB protocols? As I understand it, only problems are with non-standard proprietary drivers so Ubuntu could have problems but Windows should be fine. Fast Start-Up obviously is unnecessary and risky; and Bitlocker scared me from first contact (ship computer with it enabled, where just booting up in Safe Mode can trigger a lock-out??), but I am in an insane threat environment & likely target, so would like Secure Boot, if possible, if it can give any additional protection
  
  – mako34
  Apr 13 at 22:04
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  An install with secure boot disabled will install the unsigned versions of the bootloader grubx64.efi. Turning secure boot on will then prevent grubx64.efi from booting, and there is no shimx64 either. That's why I like to install with secure boot on, then turn it off if necessary to install third party drivers. The system would then boot with secure boot in either state.
  
  – ubfan1
  Apr 14 at 1:18
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @ubfan1 Thanks! I edited the text to make it clearer.
  
  – user68186
  Apr 14 at 1:27
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Oh God, so it was stupid to install with SB Off, Ubuntu could say "dual install with SB on but then shut it off if there are boot problems!!" Can I convert grubx64 to shimx64 or delete it and load the latter? Can you elucidate on SB action with shimx64 - does it actually examine (integrity) the GRUB boot at all, or just ignore it; does it ignore the Windows boot sector (in which case viruses too would be bypassed) and go directly to Win startup?
  
  – mako34
  Apr 14 at 2:41
  

  
  
  
  

 | 
show 3 more comments

Secure Boot

1. Ubuntu installs differently when secure boot is disabled.

When Ubuntu is installed in the UEFI mode with secure boot disabled, it installs EFIubuntugrubx64.efi.

When Ubuntu is installed in the UEFI mode with secure boot enabled, it installs EFIubuntushimx64.efi.

If you enable secure boot after installing Ubuntu, the Ubuntu will not not boot if the shimx64.efi does not exist.

The difference between shimx64.efi and grubx64.efi is that shimx64 is the actual Microsoft signed binary that works with Secure Boot enabled while grubx64 is the normal grub binary (Not signed).

2. Some third party device drivers can only be installed when secure boot is disabled.

The third party device drivers may not load and thus, some specific devices will not work.

See Is re-enabling Secure Boot in UEFI secure? for more.

Fast Start-up

Fast Start-Up or fast-boot can mean two things.

I assume this is the option in Windows 10.

This is not the UEFI option that skips the boot setup and boot device select menu when the computer boots.

Fast Start-up does not shut down Windows properly, and puts it in a hibernate state when Windows is shut down. This means all the partitions that are accessible by Windows (C:, D:, etc) are not properly shut down. Ubuntu will not be able access these drives properly in this state. In particular, you will not be able write files, including copy, move, etc., to these partitions when you use Ubuntu. This will be an issue if you have a common partition that you share between Windows and Ubuntu.

See Unable to mount Windows (NTFS) filesystem due to hibernation this answer for more explanation.

Bitlocker

Enabling Bitlocker in Windows will also make the Windows partition inaccessible from Ubuntu.

There may be ways to get around it. See Use (Windows) BitLocker-encrypted drive on Ubuntu 14.04 LTS

Disclaimer: I have not tried any of these things. So, there may be other consequences of enabling Secure Boot, Fast Start-up, and Bitlocker I am unaware of. Use at your own risk.

share|improve this answer

edited Apr 14 at 1:25

answered Apr 13 at 16:49

user68186user68186

17.2k85074

share|improve this answer

edited Apr 14 at 1:25

answered Apr 13 at 16:49

user68186user68186

17.2k85074

answered Apr 13 at 16:49

user68186user68186

17.2k85074

answered Apr 13 at 16:49

user68186user68186

17.2k85074