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How to compress VM imported from Boot Camp

  • Parallels Desktop 7 for Mac Standard Edition


You are unable to compress the virtual machine imported from Boot Camp partition. You are getting the error message:

Hard disk 1 used by the virtual machine "Boot Camp" cannot be compressed.
The disk is either plain, or dynamic, or contains no data. Such disks cannot be compressed.


After import, Boot Camp based virtual machine still has at least one GPT partition. GPT partitions cannot be compressed by Parallels Desktop image tool - this format is not supported for compression. 


In order to compress the imported virtual hard drive you need to remove GPT partitions. This is the way the imported hard drive looks right after migration:
(In order to see your partitions - right click My Computer and select Manage)

In order to remove partitions please use diskpart utility which can be started through the Command Prompt:

1. Make a full backup of the virtual machine.
2. Start the virtual machine and Command Prompt from the Start menu ► cmd.exe
3. List all partitions:

DISKPART> list disk

The output should be similar to:

Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          298 GB   128 MB

4. In order to remove partition - select disk:

DISKPART> select disk 0

The output should be similar to:

Disk 0 is now the selected disk.

5. List all partitions:

DISKPART> list partition

The output should be similar to:

Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    Primary            200 MB    512 B
  Partition 2    Primary            266 GB   200 MB
  Partition 3    Primary             31 GB   266 GB

6. Select partition to remove:

DISKPART> select partition 1

The output should be similar to:

Partition 1 is now the selected partition.

7. Delete the selected partition:

DISKPART> delete partition

The output should be similar to:

DiskPart successfully deleted the selected partition.

8. Repeat for all partitions which you wish to remove.
9. Exit Diskpart:


NOTE: Windows XP moves partitions as you remove them, e.g. Partition #2 becomes Partition #1 if you remove Partition #1 before that. Ensure you are selecting the exact partition you wish to remove before executing the delete option. After you have removed all GPT partitions, change the boot partition number in Boot.ini file which executed the system boot at Windows startup. Go to C:\Boot.ini (hidden) file and change the partition number (e.g. in the example above - change partition number from 3 to 1:


This is the way Computer Management will look after the full command execution:

223eaea75536b1878213dd8e38ab608d 1e5db16426987d561060acdf56d947b4 a9c6e0b6a5209e617a7c0dd5eace86cf

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