OEM means Original Equipment Manufacturer, so if you bought a hp computer laptop or a hp desktop computer, the OEM info displayed in the control panel in system volume information.
Just in case for any reason you want to change this information and take the complete ownership of the computer, or you just to play with it so you can amaze your friend by changing the OEM info with some simple tools which we are going to mention, these tools are FREE to use.
By modifying the OEM info you can change the manufacturer name, Edit OEM logo image, Hardware Upgrade the OEM settings and other OEM info displayed in the Control Panel.
Here are two different OEM editors for windows vista and xp