@Alvin. It depends on the machine purchased with the media provided under the OEM license. Therefore, such media-less machines are provided with a system image manager via the manufacturer or the OS and upon bootup, the machines will always prompt the end user to create a system image of the entire bundled licenses. The re-installation is limited to one install as per the OEM license, not an unlimited scenario. 

 

@Edward, when purchasing any computers kindly ensure that you select machines which provide the media option such as downgrade rights or re-installation images . These machines tend to cost a more than the OEM pre-built ones and are considered as business machines. Some entry level machines that have Win7 will also not ship with system imagers so you have to use the OS to create an image set.

 

HTHs.