If you just bought a computer from Original Equipment Manufacturer (OEM) like HP, Lenovo, Dell, etc most like you will have Windows 7 preinstalled. That being said, your computer are branded with a particular OEM brand.
For most of the ordinary users out there that is perfectly fine. But for some, they prefer to mess with that and put in their own brand. So, for these people, I have a tool for you.
The Ultimate OEM Info Editor
You can now easily add or edit OEM information in the System Properties window using OEM Info Tool. You can change anything for manufacturer name to support phone. OEM Info Tool works great in Windows Vista and 7.
Make sure you backup your current OEM info first before messing around with it. If you have messed up with your OEM info and decided to get back the default, just use the restore option.
Note: If you install your WIndows fresh from the DVD, you will not have these info. You can use OEM Info Tool to add your own.
More info and download here.