Not sure what yoyo's link says but this is how I did it thanks th madmatt>
System Logo
C:\WINDOWS\System32\
oemlogo.bmp
oeminfo.ini
OEMINFO.INI must have this format, use as many lines as you want, just keep adding to the line number. get it?
[Support Information]
Line1=info here
Line2=more info here
Line3=
Line4=and so on.
[General]
Manufacturer=yeah, you pick a name
Model=type, whatever
OEMLOGO.BMP
I forget the size, but you can create an image of like 180x110 or so pixels, make it transparent, so on. Have fun.