JSI Tip 2482. Some laptop computers may incorrectly have the option to upgrade Basic Disk to Dynamic Disks?

Microsoft does not support Dynamic Disks on laptop computers.

The option to upgrade to Dynamic Disks is normally not available on a laptop, but some models may have it, because they are not listed in %SystemRoot%\Inf\Biosinfo.inf (the BIOS information file), as they do not support APM or ACPI.

Most laptops do not support multiple disk drives and can't take advantage of the advanced volume options provided by Dynamic Disks. If the laptop supports additional drives in a docking station, it is normally absent for long periods, possibly causing corruption on reconnections. Because my laptop can mount a 2nd 25GB drive in the case, and still be mobile, Dynamic Disks are supported.

When 2 or more Dynamic Disks exists, a small 1MB database, containing partitioning and FT volume membership information, is replicated accross all the Dynamic Disks in the disk group, providing a measure of redundancy.

To disable the Upgrade to Dynamic Disk option:

1. If Dynamic Disks exist, delete any volumes on them and revert to Basic Disk.

2. Use Regedt32 to navigate to:


3. Double-click the Start value name and change it to disabled, 0x4.

4. Shutdown and restart.

NOTE: To determine if Dynamic Disks are supported, navigate to:


If the data value of DockingState is 0x1, Dynamics Disks are NOT supported.

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