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I've installed Windows 7 Proffesional SP 1 from an empty drive for HP Pavillion g4-1004tx and using it without problem for many months. Recently, I want to install linux and starts to realize that the boot partition is taking too much space (900MB!). I know the boot partition's purpose and am aware of it since Vista. But as I remember, it usually only uses about 100 - 200 MB. 900 is obviously too much. It even only uses 40-50 MB of that partition!

Is there any way I can fix this? Oh, I'm using Windows 7 with Academic Lincense (MSDNAA) if it makes any difference.

Here's the partition as taken from Computer Management tool:

enter image description here

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This is not "MBR", but the boot partition. A MBR is always 512 bytes long. – grawity Sep 3 '11 at 11:53
i see. i will edit the question. EDIT: I can't make a new tag for boot-partition. Can anyone help? Thanks. – bertzzie Sep 3 '11 at 11:56
Psst! It's actually the system partition in Microsoft terminology. You can see this in the very Disk Manager display that you're showing us. Notice the word "System" there, and the word "Boot" on the other partition. – JdeBP Sep 4 '11 at 4:03
up vote 2 down vote accepted


Part 1 - Copy the Booting Files and Configure the Windows 7 Partition for Booting

Boot into Windows 7.

To allow access to the System Reserved partition, use Disk Management to assign a drive letter to it: Click the Start button. Right-click on Computer. Click on Manage in the pop-up menu. Computer Management will open. Click on Disk Management in the tree on the left side. Right-click on the System Reserved partition and select Change Drive Letter and Paths... from the pop-up menu. Click the Add button. An available drive letter will automatically be selected. You can keep it or select a different one. When finished, click the OK button. In this example, E: will be assigned to the System Reserved partition. Leave the Computer Management window open (it will be needed again in later steps).

Note: If an AutoPlay window pops up, just close it.

Click the Start button and then on Computer to open Explorer.

Make note of the drive letter assigned to the System Reserved partition and the letter assigned to the Windows 7 partition. In this example, C: is the Windows 7 partition and E: is the System Reserved (booting) partition.

Note: It's a good idea to give the partitions meaningful labels. This can help you tell them apart more easily. For example, the label for the Windows 7 partition might be Win7. This can be especially helpful when trying to tell which partition is which from the Command Prompt.

Close Explorer once you've determined the drive letter assignments.

Start an Administrator mode Command Prompt. To do this, click on the Start button, then All Programs, then Accessories. Right-click on the Command Prompt item and select Run as administrator from the pop-up menu. If a UAC prompt is displayed, click the Yes button.

Unload the BCD registry hive by running the following command:

reg  unload  HKLM\BCD00000000

Copy the bootmgr file from the Vista (booting) partition to the Windows 7 partition (make sure to use the drive letters as assigned on your computer). Run the following command: robocopy e:\ c:\ bootmgr

Copy the Boot folder from the Vista (booting) partition to the Windows 7 partition. Run the following command:

robocopy  e:\Boot  C:\Boot  /s

The booting files have now been copied. If you wish to verify that they were copied correctly, run the following command (make sure to use the drive letter of the Windows 7 partition):

dir  c:\  /ah

If the bootmgr file and the Boot folder show up in the list, the procedure was successful.

To update the copied BCD file so it will boot correctly, run the following command:

bcdedit  /store  c:\boot\bcd  /set  {bootmgr}  device  partition=C:

Note: If your Windows 7 partition is assigned a letter other than C:, make sure to use that value instead.

Note: If you are using BootIt BM, you can use the BCD Edit feature to update the BCD file instead of running the above command. See Part 2 - Step 3 for details.

Close the Command Prompt window.

Remove the drive letter assignment from the System Reserved partition and set the Windows 7 partition as the Active (booting) partition.

Return to Disk Management (in the Computer Management window). Right-click on the System Reserved partition and select Change Drive Letter and Paths... from the pop-up menu. Click the Remove button. Click the Yes button to confirm the change. Right-click on the Windows 7 partition and select Mark Partition as Active from the pop-up menu. Click the Yes button to confirm the change. You should see the Active tag move from the System Reserved partition to the Windows 7 partition. Close the Computer Management window. Windows 7 should now be configured to boot properly from its own partition.

If you now wish to resize the Windows 7 partition to use this space, proceed as follows: Select the Windows 7 partition and then click the Slide button. Enter 0 in the Free Space Before box. Click the OK button. Read the warning and then click the Continue button to proceed. Once the slide has completed, verify that the Windows 7 partition is still selected and then click the Resize button. Click the OK button to error check the file system. Adjust the New Size value to what you want. Setting it to the Max Size value will resize the partition to use all available free space. Click the OK button. Read the warning and then click the Continue button to proceed. When the resize and error check has completed, click the Close button. Return to the Boot Menu and boot into Windows 7.


Source of Information

I suggest you make this disc before you remove the System Partition


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From what I can recall about Windows, the size of partition is not a floating number, e.g. it doesn't magically change on it's own (unless its a dynamic disk). Are you sure this is a boot partition and not some vendor installed recovery partition. Most vendors don't provide media for reinstalls on their boxes anymore. They usually create a hidden partition that contains all of the relevant software to reinstall everything on your machine. Something like that would certainly be in the ~900M range. Either way, It looks like you have a 500GB disk so 900M by today's standards is nothing to even blink an eye at. If you wanted to install Linux go ahead and do so. Just don't change that partition (boot) because I'm relatively certain that is how you recover your box.

Disclaimer: I am not a native Windows user, my answer is based on my experience with Windows in the past. If I'm totally off the mark I apologize.

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I'm pretty sure it's not vendor installed, since the laptop comes with FreeDos. Thanks for the suggestion though. – bertzzie Sep 3 '11 at 12:38
So the machine didn't come with Windows pre-installed? – C0D3M0NK3Y Sep 3 '11 at 12:40
Nope. I install it from an empty partition. That's why it bugs me, because for other machines, it's all 100 - 200MB. – bertzzie Sep 3 '11 at 12:44
This is a relatively interesting facet. Presumably, FreeDOS is still installed? If so it is likely that it is resident on this 900M partition. If FreeDOS isn't still installed, I'm at a loss on this. Either way, it won't affect your end goal of instlaling Linux. – C0D3M0NK3Y Sep 3 '11 at 12:53
Nope, I've formatted the whole drive before installing. Strange isn't it? I'll start installing Linux tonight of course :D – bertzzie Sep 3 '11 at 13:11

I'm assuming you want to keep your Windows operating system, otherwise you can just delete all your partitions when installing linux.

Question. If your Windows partition was 109.51 GB instead of 108.51, would you worry about reducing it by 1GB? If not, then why worry about the size of the system recovery partition?

If you do decide to resize this partition, there are no built-in windows tools that will do this, so you need a third party tool like EaseUS Partition Master or GParted.

You will also need to shift your windows partition up which means you should back it up first.

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