How to: Dual-boot (preinstalled) Windows 8 and Linux - UEFI etc.

Move complete

Possibly I missed it in the above … but when I initially went to shrink a Windows8 from 222 GB it would only allow me to shink it 50% (ie to 111 GB). I then managed to shrink Windows8 from 222 GB to 63.5 GB … In order to do this, I had to disable the Windows8 pagefile, disable the Windows8 hibernation file, disable the Windows8 system restore, disable the Windows8 writing debugging information, conduct a Windows 8 disk cleanup, reboot, defrag the Windows8 drive,reboot, and then shrink the Windows8 partition. I think I could have reduced this to be smaller than 63.5 GB, but upon further reflection decided just over 60GB was a good size for Windows8. After the size reduction was complete, I re-enabled those Windows8 features.

I followed the guidance here: shrinking Windows 8 partition for dual boot

Thank you for pointing that out!

I have not mentioned any such shrinking techniques here, but I will include it in the improved version of my write-up.

There are even more techniques that can be applied to wring even more (free) space out of a disk - particularly, if the disk has been in use for a while the gain can be substantial. The easiest trick is to use a 3rd party defragmenter such as MyDefrag or UltraDefrag - and even combine them. These can be configured to defragment any file of any files size, which will move even more files to the beginning of the disk. The Windows 8 defragmenter doesn’t do that, and I have seen no method to configure it (I haven’t studied W8 in that area yet). Thus, W8’s defrag will leave some files behind.

BTW: The good thing about MyDefrag, is that it can do everything in a single defrag, and it defaults to defrag every file no matter the file size (choose Monthly System Disk).
There’s one pitfall though in using 3rd party defragmenters: Windows defragmenter is a background process as well as something you can command yourself. Different defragmenters will conflict in how they move files, as they all employ different algorithms. Only use one file defragmenter at a time!
I always disable Windows defragmenter when I enable 3rd-party defragmenters, though. I have yet to must look up how to do that in W8, and also what the free-disk requirement is for W8 to do proper defragmenting. Earlier, you needed 14% free disk space to properly defragment. Less space than that would harm your defragmentation results.

As for free W8 disk space, the defragmentation-limit-value I mentioned above also goes for normal Windows use. With less free disk space, Windows will take a performance hit. Over time Windows will grow on you, so you need to repeat some of the tricks you pulled when shrinking disk to reclaim that space. I’m not sure it is 14% for W8, though… BleachBit will combine a few of your clean-up tricks in one operation, and will also take care of even more areas. Again, your use of that tool will increase with how much you use Windows.

It might be worth pointing out, because I have found few people actually realize this…

That windows 8 shutdown is now not a shutdown unless you alter the settings. It defaults to a hibernation mode for quick booting.
I have people thinking it’s fast to boot, but it’s not. If you take this stupid hibernation mode out, it’s a slow as ever it was.

This is an important point some Dual boot with Linux user may not be aware of.

BTW that 50% shrinkage was also my experience but on Windows 7 using its disk management tool. So it appears no change there then. :\

On 2013-06-25 04:26, caf4926 wrote:
> It might be worth pointing out, because I have found few people actually
> realize this…
> That windows 8 shutdown is now not a shutdown unless you alter the
> settings. It defaults to a hibernation mode for quick booting.
> I have people thinking it’s fast to boot, but it’s not. If you take
> this stupid hibernation mode out, it’s a slow as ever it was.
> This is an important point some Dual boot with Linux user may not be
> aware of.

Very important, because you can corrupt the Windows side from the Linux
side if you don’t disable that feature.

Cheers / Saludos,

Carlos E. R.
(from 12.3 x86_64 “Dartmouth” at Telcontar)

Accidentally, or did you mean with a deliberate attempt to corrupt?

On 2013-06-25 16:06, consused wrote:
> robin_listas;2567160 Wrote:

>>> This is an important point some Dual boot with Linux user may not be
>>> aware of.
>> Very important, because you can corrupt the Windows side from the Linux
>> side if you don’t disable that feature.
> Accidentally, or did you mean with a deliberate attempt to corrupt?

Accidentally. No, it has not happened to me. I think it is on the
release notes, it was commented at least.

If you use that fast mode in W8, as it does an hibernation, the
filesystem is in opened state. To use it from another OS, you have to
run an fsck on it, same as on a corrupted filesystem. If you boot
Windows later, which thinks that the system is still in opened state,
and it writes the pending changes, then further and real corruption may

Cheers / Saludos,

Carlos E. R.
(from 12.3 x86_64 “Dartmouth” at Telcontar)

That sounds to be the same as I mention in Part4 Preparation (posting #4), item 4.7 first bullet, but I mention it as a reason to stopping W8 from cluttering up the EFI NVRAM (as will hibernation).

However, curiously enough, I have not noticed any change at all in boot speed due to disabling W8 fast-boot on my Asus. I haven’t timed it though, I just can’t say it is any faster than it used to be. However, my PC has a BIOS setting (well - UEFI firmware setting to be exact ;)) that is to allow for fast boot, which I do have enabled. The documentation says this is to allow OSes to commence booting without waiting for HW-devices to become ready. nownow.dfdI

How much you will be able to shrink will depend on how you have been using Windows previous to attempting to shrink its partition. Also, with the right preparation you will be able to shrink more - provided there is more than 50% space available. Now - THAT may sound like logic that shouldn’t be necessary to explain, but it really depends on the files’ location on your partition just as much as how much space is in use. If the right files are located in the wrong places, you will not be able to shrink anything at all.

What you are looking at here is file positioning policy, not how much MS or the OEMs fills your disks…

But I’m pretty sure (I’d have to double check) windows only truly powers down if you press the Power Button (physical button on the machine). You make the changes in the control panel, but ‘Shutdown’ from the UI menu in Win8 doesn’t power off the machine.
I fiddled with this for ages, so it’s fairly clear in my mind.

I have not done a shrink yet on windows 8. My install on this G550 was direct in to a single NTFS windows 7 partition (sda1 primary)
Yes, you can install windows 8 in to a single partition.
But I tell you, the installer is horrid. Totally lacking for an advanced user.

I take it that you have disabled fast start-up. If so, then selecting

  1. <Wkey>-I --> Power --> Shut down 
  2. <Wkey>-I --> Power --> <Shift>-Shut down 

should be equivalent. If fast start-up is enabled, then the first alternative will do the “half-way hibernation”/hybrid-sleep that is the hallmark of fast start-up, and the second alternative will do a proper power off.

A way to test which mode is active for each, at least on my Asus *), is to attempt to enter BIOS setup after powering on. That will only work when the PC is in a proper powered off state. (Since W8/UEFI has intentionally shortened POST times, you may need to push-and-hold your “Enter BIOS” button prior to powering on your PC).
This behaviour is consistent with official documentation as quoted on many well reputed web-sites, but I have not had any luck yet tracking it down on Microsoft’s site, except for a FAQ which isn’t detailed enough to answer this, but it indicate this behaviour.

There’s another way too, to check the setting, but the procedure for switching off fast start-up (posting #4), should affect what is viewed here, also:
<Wkey>-X → “Power Options” → “Change Plan Settings” on the plan you are using. Then “Change advanced power settings” → “Sleep” → “Allow Hybrid Sleep”. If you have a portable, there should be two values, and both should be set to “Off”. If it is a desktop computer, you may only have one alternative there, but it should still say “Off”.

*) Actually, I used my friend’s twin Asus. We bought one each at the same time (I said it was a bargain! ;)) and that does not have OpenSUSE dualboot. I must I admit that until I get the feel for how to navigate in UEFI NVRAM and ESP partition contents, I try to avoid challenging their contents. My Asus is very stable at this (there are issues, though, but not in this area)

I really don’t want to bother checking right now.
Needless to say, it’s totally a moronic and convoluted process.

I don’t have UEFI either just FYI

Then POST speed is as it always has been, and (BIOS) POST are in control of the keyboard as before. Entering BIOS setup-mode or not will not work as a test in this case.
However, when you get to it, you should be able to test using F8 when Windows 8 is booting up, to attempt to get to Windows 8 boot-options (Safe Mode among others). That key is under Windows’ control under both good-old BIOS mode as well as UEFI mode.

The time-window available for pressing F8 may have narrowed for BIOS-mode as well, and is known to be as short as 200ms (depending on PC processing power). Thus, you may need to press-and-hold F8 during boot just as you now need to do for UEFI mode, to reliably succeed in entering Windows 8 boot-options screen.

Just a note of thanks to dayfinger for all of the above, and also the preceding 6 steps, and also to perhaps help others based on my experience with a OpenSuse 13.1 DVD and a Dell 23-30 All In One computer install.

Regarding the Dell 23-30 and OpenSuse 13.1:

I pre-partitioned my spare disk space using GPARTED-Live (ver and created a separate partition for /boot/efi which I sized to 158MB, that size came from my previous OpenSuse 12.3 UEFI install, actual space used is about 5.9MB so 158MB is more than adequate
I than configured swap, root, and home as needed and quit out of GPARTED.

Next steps for me were as follows:

Boot into secure mode using the F12 key per the following:
Insert the DVD into the DVD drive and then do a restart of the Dell using the F12 key to select the secure boot mode of the OpenSuse DVD;
After completing the various screen prompts and getting to the partitioning screen of the install I selected custom partitioning as the install disk wants to load GRUB2 efi into the Win 8 /boot/efi partition which leads to a non-booting solution, for me, after the first selection of Win 8 from the Grub/OpenSuse boot menu which then left me with the option of playing with the Dell Bios screen or using MSFT’s BCD or Easy BCD. Neither of those options were appealing to me so in the install partition screen, using the custom partition option, I used the /boot/efi partition previous created in GPARTED and set it up to be formatted as /boot/efi and then had the partition editor format it and then swap, root and home then clicked on okay and then completed the rest of the install.

After the above sucess! I now have a workable boot menu with either OpenSuse 13.1 or Win 8.1 bootable with no special intervention on my part required either after a restart or a shutdown and restart.

Also a thanks to oldcpu for his questions based thread on UEFI regarding his new laptop, as well as thanks to N Rickert, JMcD, and M Lewis for their comments, links, blog posts etc regarding UEFI implementation.


Ok I have a Toshiba Satelite S75t-A7220
Touch Screen 12 Gigs Ram ! terabyte HDD
Quad core I7 2.4Ghz
Did the entire steps you posted and it was a no go
I updated my bios was able to Disable Secure boot and change UEFI to a Normal CMOS
Still No go I can run Fedora Live but I don’t want Fedora I like Suse used it for years but not even Suse live will work
Please help>:)

‘No go’ is not very precise and it is incredibly difficult to guess as to exactly what failure symptoms you experienced. Please, can you be more specific as to the exact symptoms which constituted this ‘no go’ ?

EasyBCD does not work with GPT/UEFI.

Thank you for commenting. Yes. I have seen that quoted several times in openSUSE forums. Did you try it yourself? For what and in which scenario?

I am asking because I am questioning whether that is true. Here’s why (disclaimer: I have not used EasyBCD myself):

When I wrote this how-to, the EasyBCD manufacturer claimed the same as they still do: EasyBCD v2.2 is compatible with GPT/UEFI. At the time, v2.2 was pretty new. Were the users complaining at that time updated to that version? I know from my reading that many weren’t. That version (v2.2) seems to still be current (although it received a revision update in November), but I cannot be sure without registering at the manufacturer’s web site. That tells me that the manufacturer is probably right, at least partly, as anything else would be a scam. I have a hard time beleiving that, particularly since it isn’t that difficult to find EasyBCD success stories. I’ve stumbled over a few when trying to learn the BCD database. In addition reviews are fairly positive. However, when I am reading EasyBCD manufacturer’s claim today, they have an addition to their statement that I cannot remember reading in June 2013 (see what follows the 2nd comma): “As of EasyBCD 2.2, EFI/UEFI and GPT disks are fully supported, but some options may not be compatible with EFI machines.” (

When looking at EasyBCD back in June, I also remember reading someone saying something along these lines (unfortunately, I cannot find it now): “BCDEdit can do everything EasyBCD can do, but since EasyBCD has a GUI to guide you instead of BCDEdit’s highly fragmented documentation, it is much easier to use.”

Still, I do see that some people are struggling to get EasyBCD to do what they want. No doubt, these users have problems, but somehow it has always been unclear what and where the EasyBCD error occurs in these cases. They are also quickly advised off EasyBCD (here in the openSUSE forums) and offered alternative solutions. I am not saying that there is anything wrong in such an advice, but I have not seen any real proof of EasyBCD failing, either. There are also e.g. combinations of UEFI/GPT and MBR that do not work together (under Windows - and both BCDEdit and EasyBCD only work under Windows). Could it be that - since EasyBCD is so easy to use, it is just as much abused? Abused by experimenterers that doesn’t really understand what is going on - and that prevents them (and EasyBCD) from doing what they want? And, since EasyBCD is the tool being used, it gets the blame too?

So, to repeat myself, I am questioning whether it is true that EasyBCD doesn’t work with GPT/UEFI. I would expect that 6 months later, they wouldn’t be allowed to add e.g. Windows 8.1 to their fully supported OS check-list without that resulting in some kind of protest that would be fairly visible on the web, and they would have flunked all reviews. Saying that a feature is working for MBR and not for UEFI/GPT doesn’t mean that the product is broken. It may not be possible to do it (or it requires so much effort to support that it hasn’t made it to a release (yet) because UEFI/GPT and MBR are different. Since EasyBCD works from inside Windows, it has to work with what Microsoft has decided to offer from within their OS. All of these are limitations EasyBCD cannot easily escape. To top it out, there are flawed UEFI implementations that can be thought to stop EasyBCD from doing its work *even if EasyBCD is doing everything right *wrt e.g. NVRAM entries, and that could easily be blamed on EasyBCD, instead of (rightfully) the manufacturer’s UEFI. In such situations, EasyBCD may not be so easy after all, since it does many things and everything is done without you seeing it. In such cases, BCDEdit and efibootmgr are probably more helpful. Which probably makes the advice of leaving EasyBCD behind, a sound advice after all.

Myself, while relying on Grub2 for (dual)booting, I have found a way to use BCDEdit to resolve anything I’ve wanted to do to date in this regard within Windows. So far, I’ve seen no need for EasyBCD. Most of my BCDEdit ‘tricks’ has been entered in postings of mine in the Install-parts of these (openSUSE) forums. There are several other threads, but these are the ones that comes to mind atm: