Using Acronis Disk Director 10 to Change the
Hidden Sectors field of an NTFS Logical Partition

Start DD and make sure you're in "Manual" mode.

Then Right-Click on the Logical Partition that contains your XP installation and select the Advanced menu and then the Edit item from the sub-menu. (In this example, I'm just using one of my NTFS Logical data partitions.)

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.

This is the BEFORE image. Notice that the partition starts on Absolute sector 157,356,738, but the Hidden Sectors field (shown below) says "63" (which is the default for the first Primary partition).

Click in the Hidden sectors textbox and type in the 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).

More information on booting XP from Logical Partitions can be found here: (scroll down to the "Fixing Boot Records in Logical Partitions" section).