Solved 100 MB Partition

[bigmck]

I have read on here about the 100 MB partition for the MBR. I don't have one. Things seem fine. What is the partition for and do I need to worry about it? Thanks

 

[Bill2]

The 100 mb partition, when present contains files required for win7 to boot. Its created only when win7 is installed on a disk with unallocated disk space (no partition or volume been defined yet). Its labeled as System Reserved with NTFS file system, and System, Active, Primary partition attribute with no drive letter in Disk Management.

When the 100 mb partition is not created, the boot files sit on the OS partition itself. So, nothing to worry about.

 

[Bare Foot Kid]

Hello.



If you did have a desire to create it for whatever reason (I'm not suggesting you do) here is a very reliable method out-lined in this tutorial at the link below; the second tutorial is also an excellent option, though I still have some work to finish that one to an acceptable out-come for XP.

System Reserved : Create for Dual Boot

System Reserved : Create Using Disk Management



This second tutorial is now complete.





.

 

[bigmck]

Thanks guys for your help. I am a little paranoid these days. I feel like anything could go wrong since a few days ago my water pipe broke in the front yard.

 

[Bare Foot Kid]

Thanks guys for your help. I am a little paranoid these days. I feel like anything could go wrong since a few days ago my water pipe broke in the front yard.

That's the hard way to water-cool the PC isn't it?

 

[gregrocker]

If you can spare the 100mb then I'd install to wiped HD (which is a cleaner slate anyway) to get the SysReserved partition - if for no other reason than that it places the Repair My Computer (WinRe) console on the F8 Advanced boot Tools menu. You can repair your laptop in a coffee shop or while traveling without having to have the disk.

Wipe HD: http://www.sevenforums.com/tutorials/91339-ssd-hdd-optimize-windows-reinstallation.html
Install screenshots: http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html
WinRe options: http://www.sevenforums.com/tutorials/668-system-recovery-options.html

 

[mickey megabyte]

If you can spare the 100mb, then I'd install to wiped HD, which is a cleaner slate anyway, to get the SysReserved partition - if for no other reason than that it places the Repair My Computer (WinRe) console on the F8 Advanced boot Tools menu. You can repair your laptop in a coffee shop or while traveling without having to have the disk.

thanks for that greg - i was thinking about deleting mine, but i may well keep it now, especially on my netbook.

 

[Bare Foot Kid]

Here's some other info on the SysResv I wrote for one of the other tutorials but I didn't use it after all.

   Note

• It adds a link to the WinRe (Windows Recovery Environment) that is seen when the advanced boot options are accessed through the use of the F8 hot-key during system startup that can be used to recover from startup errors if a Windows installation / recovery disk is not available for use.
• The partition is suggested for use with Windows Backup and Restore to function correctly, we're now seeing issues if not enough space is available for WB & R to use and creating a larger (than the default 100MB) SysResv partition may solve these issues.
• It is used by Windows 7 BitLocker to store encryption information and will be created by the BitLocker program if it does not exist.
• It creates a single location for the Windows BCD store that the system boot files are kept in, in a dual / multi boot situation and makes removing one of the installed Windows Operating Systems (OS) in a dual/multi boot very easy to accomplish if the need arises.

 

[Bare Foot Kid]

If I was going to go to all the trouble of a clean install to get the "System Reserved" partition I'd use the method out-lined in Step Two #3 of this tutorial to make it 200MB instead to lessen the chances of it being too small like the issues THIS guy was having when he wanted to add a second OS for a dual boot setup.

SSD / HDD : Optimize for Windows Reinstallation



We're starting to see a lot of these similar issues with the default SysResv being too small; not to mention the uses listed in the Note in my post above.

click to enlarge


​

 

[mjf]

I have read on here about the 100 MB partition for the MBR. I don't have one. Things seem fine. What is the partition for and do I need to worry about it? Thanks

I've just about given up arguing the MBR point living on the 100Mb sys reserved partition. I don't understand why people dig their heals in on this. It is the first physical 512 bytes of the HDD. If you can show me that the MBR is on the 100MB partition please show me.
I'm only aware of the WinRe living in 2 places
(1) Under a system folder called "Recovery" (c:\Recovery) on your Boot, OS partition which is separate when you have the 100MB sys res partition.
(2) On the System repair disk, or Install disks.

The 100MB partition contains it's boot sector (PBR), boot manager, BCD store, a memtest utility and a system volume information folder.
The 100MB partition may play some role in recognising the F8 key stroke (??) but I bet it uses the WinRe under the system recovery folder. Remember WinRe is greater than 160MB itself.

 

[mickey megabyte]

the plot thickens

 

[gregrocker]

I haven't explored just how SysReserved places WinRe on the F8 Advanced Boot Tools menu, only that it does.

Even on a Win7 factory install which customizes WinRe to contain Factory Recovery, there is always a SysReserved partition in the mix.

As for MBR, referring to it being "on" a certain partition is common shorthand around here for "System Active." It is simply too complicated to explain otherwise.

 

[mjf]

I haven't explored just how SysReserved places WinRe on the F8 Advanced Boot Tools menu, only that it does. Even on a factory install which customizes WinRe in Win7 to contain Factory Recovery, there is always a 100mb SysReserved partition in the mix.

As for MBR, referring to it being on a certain partition is common shorthand around here for "System Active." It is simply too complicated to explain otherwise, although the story of how the El Torito sector got its name is pretty cool.

Greg,
you know I bite easily...... It's not complicated.
What I know about the El Torito sector was a bunch of software engineers over a class of red figuring out how to get a CD to boot.

 

[gregrocker]

Mike - It really is both complicated and confusing to try to explain, far more than I wish to quote correctly when helping a dozen people a day resolve complicated boot problems. Perhaps it is enough that we fix more of these here than all the other forums (including MS's own) put together.

I like that story about how the boot sector was sketched out on a cocktail napkin at the El Torito restaurant in Silicon Valley. I imagine going there for lunch and seeing it framed on the wall.

 

[essenbe]

gregrocker, I only wanted to let you know that I am one of those people who refuses to have the 100MB partition. I have had three different win 7 machines with the System Reserved that caused me all kinds of grief. For some reason, the system reserved would fill up and therefore I could not do a system image or backup in control panel.

Microsoft has known that it has been a problem for numerous people but has not done anything to correct it. According to MSFT, you have to have a minimum of 40MB free space in sys res. in order to do a backup through control panel. They told me that control panel uses sys res to build a temp folder to store info for the sys image. when it gets a certain amt, it then transfers it to your backup location. but, if you do not have the 40MB backup will fail by telling you there is not sufficient space in your backup location! The correct reason is there is not sufficient space in the system reserve. I have never had a problem without the 100 MB partition. I will not deny that the sys res. has its advantages, but the disadvantages it causes me, far outweighs them.

I am not an MVP or anything close, but I have investigated this issue to the end, and am very familiar with what is happening. I know many who like it and want it and that is fine for them, just not for me.

FWIW, I am only angry with microsoft. They have known of this problem for over two years that I know of. It should be very simple for them to solve. But, they have made no attempt to try a fix. To an average person like me, the price they charge for the OS and their finicky rules about how many machines I can put it on ( for something I Bought) and them not fixing a problem that they are aware of, is inexcusable. Just my opinion.

 

[whs]

I am not a friend of the 100MB partition. But I think they have a reason to go down this route. They are preparing for EFI (an Intel developed standard to replace the BIOS). Extensible Firmware Interface - Wikipedia, the free encyclopedia

 

[gregrocker]

essenbe - I am familar with your issue as we deal with it here regularly. Perhaps SysReserved was written to during factory install or Dual Boot, or has been given a letter which lets some program write to it. Did yours have a letter?

Just yesterday here a Dual Boot couldn't be established using SysReserved. Unlettered SysReserved was almost full so I had OP enlarge his 100mb to 200mb and it was able to update the boot files.

MS must know about this by now.

 

[essenbe]

gregrocker, I can personally assure you that Microsoft is aware of the issue, as I have made such an issue with it I kept getting pushed up the ladder. They are quite aware of the issue and have done nothing to correct it. Mine did not have a letter. I can tell you my personal opinion on this issue. For some reason, by talking with others with the same pronlem one name kept popping up. Acronis. Acronis uses control panel( in fact takes over CP) for their backups. There are a few other image programs that use the 100MB partition to do their job. I think those are the culprit. I also believe from discussions that some AV programs do similar things. I guess that is their job, but it causes issues. The part I don't understand is I have helped people(with some of your tutorials here) to increase the size of the partition to as much as 350MB ( according to Microsoft I think 380 is the max). Whatever program was in there just grew with the increased size and you still could not do a system image.

 

[whs]

Just yesterday here a Dual Boot couldn't be established using SysReserved. Unlettered SysReserved was almost full so I had OP enlarge his 100mb to 200mb and it was able to update the boot files.

A while ago it was at 200MBs. I wonder why the reduced the size.

 

[mjf]

I heard from someone on the forum that MS reduced it from 200MB because of people complaining who wanted to run small SSD drives. Who knows???

Mine bounces around a bit but hasn't caused problems. If it does I'll make it bigger or get rid of it (the proper way).
Why don't you look inside it to see what's using what? The only thing I can see that can vary substantially is the system volume information folder.