If physical host machine has not enough resources or performance to keep every virtual machine running the solution is to start virtual machines only when needed. Wake-On-LAN Virtual Machine implements the Wake-On-LAN computer networking standard to turn on virtual machines. When the program starts it searches for existing Microsoft Hyper-V, Windows Virtual PC, Microsoft Virtual PC 2007, Oracle VM VirtualBox, VMware Server, VMware Workstation and VMware Player virtual machines. Then it retrieves a list of virtual machine names and their MAC addresses and shows it as a tree view. The list can be exported to different file formats. If Wake-On-LAN Virtual Machine receives a magic packets with MAC address which is in the list it turns on the found virtual machine using vendor utilities. The program consists of a Windows GUI application and a Windows service. The Windows service allows to power on virtual machines without logon to the host machine. Wake-On-LAN Virtual Machine shows log information on the screen, generates a log file and Event Viewer logs.