What is the VMC file format?
A .vmc file is an XML configuration file describing a virtual machine for Microsoft Virtual PC or Microsoft Virtual Server. It stores all the hardware parameters for the VM: its name, allocated RAM, CPU settings, paths to one or more VHD virtual hard disk files, network adapter settings (including MAC addresses and virtual network bindings), serial and parallel port configuration, sound settings, and display options.
The .vmc does not contain the VM's disk data - that lives in the paired .vhd file. Think of .vmc as the hardware specification and .vhd as the drive. Both must be present and correctly referenced for the VM to start. The .vmc also records the paths to the saved-state (.vsv) and undo-disk (.vud) companion files.
Microsoft acquired Virtual PC from Connectix in 2003. The last product to use .vmc was Windows Virtual PC, a free Windows 7 add-on used mainly for the XP Mode compatibility environment. Windows 8 dropped Virtual PC entirely in favour of Hyper-V, which uses the newer .vmcx configuration format. The .vmc format is now obsolete and is found only in archived Windows XP-, Vista-, and 7-era virtual machines.
Because .vmc is plain XML, it can be opened and edited in any text editor. Oracle VirtualBox can import .vmc and .vhd file pairs directly, making it the most practical path to running legacy Virtual PC machines today.
Security & safety
RISK: LOWVMC is a plain XML settings file - not executable and not directly dangerous. The associated VHD disk file may contain a full OS with potentially sensitive data or malware in the guest. When opening inherited VMs, treat the guest OS as untrusted (no shared folders, limited networking) until scanned.
Format details
in a nutshell- Valve Micro Controller (embedded systems) - Some embedded/automation toolchains use .vmc for microcontroller project config; completely unrelated to virtualization.
Programs that open VMC files
Windows3 apps
Oracle VirtualBox
Open-source VirtualBox does not import VMC directly, but can attach the companion .VHD disk file to a new VM manually. Create a new VM, skip the disk creation step, and attach the existing .vhd.
Hyper-V (built-in, Windows 10/11 Pro)
Built-in Hyper-V does not read VMC. Create a new Hyper-V VM and attach the .VHD file. Use Convert-VHD to upgrade to VHDX for better performance.
Notepad / any text editor
Built-in VMC is plain XML - open in Notepad or VS Code to inspect/edit settings like memory allocation or disk paths. Incorrect edits will break the VM. Technical details
deep spec| File encoding | UTF-8 XML (plain text) |
| XML root element | <preferences> containing all virtual machine configuration data |
| Paired disk format | Always paired with a .VHD virtual hard disk file; VMC = hardware spec, VHD = disk data |
| Settings recorded | RAM allocation, CPU count, VHD paths, network adapter MAC addresses, serial/parallel ports, display config |
| Companion file paths | References .vsv (saved state) and .vud (undo disk) file paths stored inside the VMC |
| Platform | Windows XP, Vista, and 7 only - not functional on Windows 8 or later |
| Products that used VMC | Microsoft Virtual PC 2004, Virtual PC 2007, Windows Virtual PC (Windows 7 XP Mode) |
| Successor format | .vmcx (Hyper-V, Windows 8 / Server 2012+) - VMC is now obsolete |
| MIME type | application/xml |
| Typical file size | 5 KB - 100 KB |
| VirtualBox import | Oracle VirtualBox can import .vmc/.vhd pairs directly without conversion |
| Released | 2003 (Microsoft Virtual PC 2004, after Connectix acquisition) |
| Latest version | Last used in Windows Virtual PC (Windows 7, 2009); superseded by Hyper-V (.vmcx) |
| Specification | learn.microsoft.com |
VMC conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about VMC files.
