If you want your VM computer auto start when the host computer is powered on, in VMware vSphere ESX, ESX4 or ESX 5 using VMware vSphere client.
1. Open VMware vSphere client.
2. Go to Configuration tab.
3. Choose Virtual Machine Startup/Shutdown menu.
4. Click Properties.
5. Give a tick on the Allow virtual machines to start and stop automatically with the system.
6. Choose the virtual machine you want to become automatically start, click Move up and put on the automatic area.