Using Disk Director to Change the Hidden Sectors field
of an NTFS Logical Partition
Contents

Introduction

Instructions

Introduction

When trying to boot a Windows operating system (XP or Vista, for example) from a Logical partition, it's necessary to change the Hidden sectors value in the partition's boot sector to the starting sector of the partition. By using this method, the partition can be booted normally from a boot manager just as if it were a Primary partition.

Instructions

Start Disk Director. You can do this by running Disk Director in Windows or by booting to the Disk Director CD.

Make sure you're running in Manual Mode. Click on the View menu and then select the Manual Mode option.

1.1

Next, right-click on the Logical partition that contains your Windows installation and select the Advanced menu and then the Edit option from the sub-menu. (In this example, I'm just using one of my NTFS Logical data partitions.)

1.2

The Acronis Disk Editor will start and show the disk. Click on the View menu and select the As NTFS Boot Sector option to view the data in the correct format.

1.3

Figure 1.4 shows the BEFORE image. Notice that the partition starts on Absolute sector 530,980,443, but the Hidden sectors field says 63 (which is the standard pre-Vista default for the first Primary partition).

1.4

To fix the partition so it can boot, click in the Hidden sectors textbox and type in the correct Absolute sector value. Then press TAB to move to another field or click into another field so the Editor knows you made a change. The Save Sector button should become enabled. Click it to save the sector (you may be asked if you want to save the changes).

1.5
More information on booting Windows from Logical partitions can be found here: http://www.goodells.net/multiboot/ (scroll down to the Fixing Boot Records in Logical Partitions section).
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