How to fix the “Cannot attach the virtual hard disk …”

… to the virtual machine. Check the values provided and try again.” error

It sucks as an error message. Would it take too much programming effort to make it more meaningful Virtual PC team?

What does it mean?

It means you have a Virtual Hard Disk file larger than 127.5GB. Which Virtual PC does not support.
You might have created this with the Microsoft Disk2VHD tool.
To confirm the “disk is too big” problem, open the Settings on an existing Virtual PC, and try to attach the drive:

In other words, we’ve captured a 160GB hard disk, and Virtual PC won’t let us use it.

But we can fix it, it’s a two step process

First we use DiskPart, and then we use VHD Resizer.

1.DiskPart

DISKPART> select vdisk file=c:\users\dale\desktop\worktest.vhd

DiskPart successfully selected the virtual disk file.

DISKPART> attach vdisk

100 percent completed

DiskPart successfully attached the virtual disk file.

DISKPART> list volume

Volume ### Ltr Label Fs Type Size Status Info ---------- --- ----------- ----- ---------- ------- --------- -------- Volume 0 E DVD-ROM 0 B No Media Volume 1 NTFS Partition 100 MB Healthy System Volume 2 D NTFS Partition 199 GB Healthy Volume 3 C NTFS Partition 265 GB Healthy Boot Volume 4 F NTFS Partition 149 GB Healthy

DISKPART> select volume 4

Volume 4 is the selected volume.

DISKPART> list volume

Volume ### Ltr Label Fs Type Size Status Info ---------- --- ----------- ----- ---------- ------- --------- -------- Volume 0 E DVD-ROM 0 B No Media ... * Volume 4 F NTFS Partition 149 GB Healthy

DISKPART> shrink querymax

The maximum number of reclaimable bytes is: 106 GB (108636 MB)

DISKPART> shrink desired=40960 (Note: desired is the amount we want to prune of the image)

DiskPart successfully shrunk the volume by: 40 GB

DISKPART> list volume

Volume ### Ltr Label Fs Type Size Status Info ---------- --- ----------- ----- ---------- ------- --------- -------- Volume 0 E DVD-ROM 0 B No Media ... * Volume 4 F NTFS Partition 109 GB Healthy

DISKPART> detach vdisk

DiskPart successfully detached the virtual disk file.

DISKPART> exit

What we now have is a VHD file still sized at 149GB, but with a 109GB partition in it. What we need to do next is resize the VHD to 109GB.

2. VHDResizer.

Use VHDResizer to resize your newly shrunk VHD file, in this example WorkTest.VHD