What is the 100mb partition Windows 7 SOMETMES creates on install?


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Windows 7 doesn't create the 100MB partition on my computer. So maybe the people that are saying that it is created only on blank disk are right because i always format my c: drive while installing windows and rest of my disk is partitioned.

I don't have any but from researching last time I thought I found out that it held the recovery data. Not the GBs worths that you find on an OEM computer with the ability to "reformat" and reinstall as was when bought but what you boot in to when your computer doesn't boot that holds the necessary tools to repair a computer such as diskpart, etc.

You can find the answer yourself by simply mounting the partition and seeing what's on it. It doesn't contain any recovery stuff, that is located in the Recovery folder on the root of the boot partition. You can also look inside this folder, where you'll likely find an image of the recovery environment around 150MB in size. In other words, too large to fit on the 100MB partition. I'm willing to bet that it's entirely version-dependent as well, meaning the recovery environment for Vista can't repair 7 and vice versa. In other words if you were to dual boot and it really was stored on the 100MB partition, it wouldn't even work. So what's left then? The boot loader and BitLocker.

You can find the answer yourself by simply mounting the partition and seeing what's on it. It doesn't contain any recovery stuff, that is located in the Recovery folder on the root of the boot partition. You can also look inside this folder, where you'll likely find an image of the recovery environment around 150MB in size. In other words, too large to fit on the 100MB partition. I'm willing to bet that it's entirely version-dependent as well, meaning the recovery environment for Vista can't repair 7 and vice versa. In other words if you were to dual boot and it really was stored on the 100MB partition, it wouldn't even work. So what's left then? The boot loader and BitLocker.

It's there primarily to allow windows to enter repair mode without the disk. it's got some tools, like the command line ones, but they're hidden in the shell. yes the actual repair files are on the system disk, but this what allows you to boot into repair mode to use them.

MS talked more about this during beta, after that it's not really even been mentioned. also in the early beta is was 200, then they managed to shrink it to 100.

And you don't need the partition, and it won't affect anythign not to have it, but if you ever need to go into repair mode to fix any **** ups, you'll need the disk then.

Do they? I can't think of any that do. No Linux distribution that I've tried do, FreeBSD doesn't, and, well, what other OSes are left that have any relevance today. I don't think it's common at all to have the boot loader on a separate partition.

Red Hat does that. And, by extension, so does Fedora. It may not be all that common, but Red Hat is the most popular server distro, so I guess it is not that unusual, either.

There is an advantage, as that partition can be mounted read-only at boot time. Plus, if some rogue process (or malicious user) gets into the system and starts filling up spaces, kernel updates can still happen as there is dedicated space for the boot process.

It's there primarily to allow windows to enter repair mode without the disk. it's got some tools, like the command line ones, but they're hidden in the shell. yes the actual repair files are on the system disk, but this what allows you to boot into repair mode to use them.

There's nothing on it other than the boot loader and memory test program. Just open it yourself and see. It's not magic, it's just a standard NTFS partition. I don't know why you believe it won't be able to start the recovery environment unless the boot loader is on its own special partition. That doesn't make any sense.

Red Hat does that. And, by extension, so does Fedora. It may not be all that common, but Red Hat is the most popular server distro, so I guess it is not that unusual, either.

Thanks, I hadn't seen that. I'm assuming it has the kernel on there as well, and not just the boot loader.

Thanks, I hadn't seen that. I'm assuming it has the kernel on there as well, and not just the boot loader.

Yes. In Linux, anyhow, the kernel images are located in /boot (whether it is a separate partition or not). Enough room is generally partitioned there for several images, so you can test a new kernel and still keep the older image - just in case.

The special 100MB system partition is created solely in support of Bitlocker. The reason it is created, even if your edition of Windows doesn't support Bitlocker, is so that you can enable it should you Anytime Upgrade to Windows 7 Ultimate. This prevents those upgraders from dealing with resizing/creating partitions.

  • 2 weeks later...

the partition will only be created when you use the Windows 7 Setup to create new partitions. If you use other tools to create and format the partitions, Windows 7 Setup will use them and won't create a new 100MB partition.

"it seems to create it on random installs"

I assure you its not "random" there are specific rules in place that would determine if the partition is created or not. Just because you are not aware of them does not mean the install flips a coin to determine if created or not ;)

As Mark pointed out using a /boot is quite common in linux distros -- can /boot be part of the same partition the rest of the OS is installed too -- sure it can. But quite often its own partition -- if you allow most any distro to partition the HDD for you, it will most likely create /boot and /var and /home /usr etc.. There are many advantages to doing it that way -- you could use smaller block sizes for specific partitions, you can recover from corrupted file system easier, might be easier to back up - just the /home part for example might be backed up.. There can be some draw backs as well if a specific partition is not sized correctly from the start, etc.

But most every linux or bsd distro I have ever used will more than likely break up the disk if given the chance to do so with auto tools, and most every guide you read about manually setting up linux will suggest you create multiple partitions for the different aspects of the OS depending on your needs.

Now I have not had the desire to dig into the rules windows uses to determine when or if a 100MB part is created.. To be honest I don't really understand the fuss about it. Its a 100MB for gosh sake -- if your worried about 100MB of space you clearly do not have a big enough hard drive for your system ;) But a quick google has lots of info on how to delete the thing -- what users get their panties in a bunch about never ceases to amaze me.

I have not tested it but it seems as already stated if you create your partition before you install and set it active, etc. then the win7 setup will not create the 100MB part and you will just see the boot files in a /boot folder on your C:\

There is really no need for any 3rd party tools - this easy enough to do with the win7 media -- when it boots just get yourself a command prompt before you move into the actual setup. Run diskpart -- create your partition you want to install to, format it ntfs and then set it active.

off the top

diskpart

sel disk 0

create partition primary (you could set size if you want)

sel part 1

format fs=ntfs

active

Now if you install to that partition - the setup will not create the 100MB, and you will get the files in a /boot folder.

But from my understanding this will prevent the use of bitlocker if you ever wanted to use that in the future. This is easy enough to test, like I said I have never actually had the need/desire to not let it create the 100MB partition.

You can avoid the 100mb being installed by pre-partitioning.

You can cancel it when it offers it at the Custom drive map screen on the installer, by using Advanced drive tools to delete the Win7 partition, then extend the intended 100mb partition to take up more space, format it and install Win7 there.

You can remove it by using Partition Wizard free bootable CD to delete, then Resize Win7 partition into that space, apply all steps, boot into Win7 DVD and run Startup Repair 3 times, which will attempt to repair before rewriting the MBR to Win7 partition.

You can avoid the 100mb being installed by pre-partitioning.

You can cancel it when it offers it at the Custom drive map screen on the installer, by using Advanced drive tools to delete the Win7 partition, then extend the intended 100mb partition to take up more space, format it and install Win7 there.

You can remove it by using Partition Wizard free bootable CD to delete, then Resize Win7 partition into that space, apply all steps, boot into Win7 DVD and run Startup Repair 3 times, which will attempt to repair before rewriting the MBR to Win7 partition.

But whyyyyy would you ever consider doing this?

The OS is meant to be run with a separate boot partition. There are features which you won't be able to enable in the future that depend upon this (including Bitlocker).

But whyyyyy would you ever consider doing this?

The OS is meant to be run with a separate boot partition. There are features which you won't be able to enable in the future that depend upon this (including Bitlocker).

Because many people want to get rid of it (not me) but botch the attempt, and I have done it for others successfully a half dozen times.

I agree, just having the Repair Console available at F8 on bootup is good enough for me. I can reimage my laptop HD in Starbucks if needed!

I agree, just having the Repair Console available at F8 on bootup is good enough for me. I can reimage my laptop HD in Starbucks if needed!

That does not use the 100MB partition. Short of BitLocker, there is really nothing you lose by not having it.

That partition was never meant to be deleted, so if you mess up your computer after installing an update or a service pack, don't come crying to Neowin and/or bash how ****ty Windows 7 is... :no:

I have Windows installed on a 60GB SSD and the 100mb partition doesn't bother me at all. It baffles me to see people wanting to get rid of this partition.

OCD much? :unsure:

That partition was never meant to be deleted, so if you mess up your computer after installing an update or a service pack, don't come crying to Neowin and/or bash how ****ty Windows 7 is... :no:

I have Windows installed on a 60GB SSD and the 100mb partition doesn't bother me at all. It baffles me to see people wanting to get rid of this partition.

OCD much? :unsure:

Don't be such a drama queen. You do know that creating the partition is actually optional right? Windows doesn't need it. It does nothing except hold the boot loader and optionally BitLocker if you encrypt your drive. Removing it or not adding it to begin with will break nothing. Not today, and not in the future. Nothing can ever be added to Windows 7 that will require it. Computers aren't actually magic, and it really is possible to understand how they work.

That does not use the 100MB partition. Short of BitLocker, there is really nothing you lose by not having it.

Maybe you can help me figure out why only the installs I do which have the 100 mb partition also put Repair My Computer console available by tapping F8 at bootup?

Also, why does deleting the 100mb require running Startup Repair which logs rewriting the MBR as the final step taken to repair it? Is it because I'm also extending the Win7 partition into that space?

Just askin.

Don't do that. Windows creates a separate boot partition for a reason. Lots of other OSes do the same thing. Don't mess with it.

Err, no. The Windows boot partition has nothing to do with the GPT Protective Partition found on most EFI / GPT systems (like Macs), nor is it related to the EISA or other recovery partitions provided by various OEMs.

It is more comparable to the common "/boot" partition created by some Linux installers.

I gave about 8 reason for use or possible use why you would see a partition in front of the Windows partition. Didn't mean specifically GPT/EFI...

Thanks for the information about it not having to do with the GPT. But I did mention bitlocker would use it ... =)

Could you give a more technical background for what Microsoft would POSSIBLY use it for besides the bit locker? Just curious and I always like to have the most correct information.

Thanks,

1Way

It contains boot files and recovery info & If you delete it you will no longer be able to boot you computer

Ive used the recovery mode once, yesterday when I disabled the write cache on one of my drives it hung device manager and I rebooted. It seems tho this setting was fatal as I got the loading logo screen and then nothing.

I then got the option on the reboot to use this recovery mode so I let it do its business and it said everything was perfect no errors found and rebooted again but of course same problem.

The good old f8 'use last known good configuration' got me back up and running again in the end.

Ive used the recovery mode once, yesterday when I disabled the write cache on one of my drives it hung device manager and I rebooted. It seems tho this setting was fatal as I got the loading logo screen and then nothing.

I then got the option on the reboot to use this recovery mode so I let it do its business and it said everything was perfect no errors found and rebooted again but of course same problem.

The good old f8 'use last known good configuration' got me back up and running again in the end.

Nice anecdote, but it has nothing to do with the 100MB partition (which holds just the boot loader, and not a single bit more.)

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