[UPDATE december 2011: Procedure might be unnecessary for users of VMware Workstation 7 and later, but I'm not really sure if Partition Magic is needed or not. Check out feedback in comment below.]

On several places it is written that it is somewhat problematic to expand the boot disk:

"...Windows DiskPart utility, it can extend (expand) only data volumes..."
            - VMware FAQ

But it is not hard to do it, and you don't need any disk utilities except diskpart.exe which is included in Windows.

The only guarantee I will give is that this has been working for me. ;-)

Follow this steps on your own risk:

1. Shut down the VMware Virtual Machine.

2. Make a complete Clone of the Virtual Machine. (Keep this clone as a backup if the procedure does not work for some reason.)

3. Locate the utility vmware-vdiskmanager.exe and the original disk file you want to expand. Open a command window and run the command below. Modify paths, file names and disk size as needed.

"C:\Program\VMware\VMware Workstation\vmware-vdiskmanager.exe" -x 8GB "C:\Documents and 
Settings\userhome\My documents\My Virtual Machines\Win2k3test\Windows Server 2003, Standard 
Edition.vmdk"

This takes some time to complete.

There's a lot more you can do with vmware-vdiskmanager.exe. If curious, se links on the VMware FAQ page above.

4. Edit the cloned Virtual Machine. Add the just expanded original disk to the machine.

5. Boot the clone VM. You will se the expanded drive on a new "drive letter". Open a command prompt and run diskpart.exe:

• Run "list volume". Look for the volume number for the expanded drive.
• Run "select volume x", where x is number for the expanded disk.
• Run "extend".  The volume will instantly be extended.
• Exit from diskpart.

6. Shut down the cloned machine and remove the expanded disk from the cloned machine.

7. Boot the original virtual machine. You should now have a larger volume.

You might want to run "chkdsk /f /r" and reboot to be sure the disk is ok. This Control take a long time to complete.

I hope this works for you! Please email me if this screws things up for you so that I can improve this guide or warn others!

Good luck!

---

Manually added feedback

February 17, 2011:

hi Walter,
this page (http://walter.thyselius.org/data/howto/vmware-expand-windows-disk.html) was a great help!
one note: step 3 can be done with the UI. I don't know though, if it's a feature of my VmWare installation (VmWare Client).
thanks again, regards,
Eling Homminga

April 27, 2010:

Thanks for the VMWare expansion instructions!
I followed your guide at http://walter.thyselius.org/data/howto/vmware-expand-windows-disk.html to expand a virtual disk and it worked perfectly.
I was using Workstation 6.5
Thanks!
Ishmael Turner Analyst / Developer

October 24, 2009

Hello Walter,
This email just to report that your procedure “How to expand/grow a Windows system/boot disk under VMWare” (that I have used before under Windows 2003) seems not to work under Windows 2008.
Truly yours
Robert Noël, ing
Conseiller en technologie / Stockage
SNIA Certified Professional (SCP)

 July 19, 2009

Worked like a charm, thanks so much!!!
James Bibby

December 8, 2009:

Hello Walter, 
I used your procedure to expand a system/boot disk in VMware.  I had a virtual 
machine configured with 10GB harddisk, and needed to increase the size to 20GB. 
It seems to work fine ... 
(it took me about 5 attempts, but when I followed the procedure exactly, then it worked ok!) 
Thank you. 
Best regards, 
Niall Mc Andrew

Mars 10, 2009:

Hi there Walter,
I read your article on
http://walter.thyselius.org/data/howto/vmware-expand-windows-disk.html
and I found it very useful! Very nice guess!
Thanks for it,
Roberto from Italy

June 6, 2007:

I found that you have to delete the swap file and the boot.ini off the original drive because the clone sees it as a system drive. Just put the boot.ini file back after expanding it.
Robert Stout