Techniques are disclosed for provisioning a virtual desktop. A VM hosting the desktop may be joined to a domain using offline domain join and customized by modifying contents of a virtual disk of the VM, as per the customization requirements, without powering on the VM. While the VM is powered off, a composer application customizes the VM by applying system and user profile configuration changes and network configuration changes, as well as optionally creating a user data disk and pushing to the VM a script for formatting said disk during the VM's first power-on. In addition, while the VM is powered off, the composer invokes a domain joining tool to join the VM to a domain controller without having to reboot the VM. A snapshot is then taken of the VM, after which the VM is then powered on and the script for formatting the user data disk executes.