How-to:
1. Paste this into Notepad (or whatever), changing the text as desired:
[General]
Manufacturer=Captain Pugwash
Model=The Black PigSave it as c:windowssystem32oeminfo.ini (overwrite the original if necessary)
2. For the nice pretty image, get a picture that's 180x115 pixels, and save it as c:windowssystem32oemlogo.bmp.
For transparency, reduce the image to 256-colour before saving. The last palette entry will be transparent.
Post more tweaks and twiddles!