You need two files in your system32 dir:
oemlogo.bmp - The image you want, needs to be about 180 x 90 and oeminfo.ini
This is my ini file lifted straight out of my system32 dir:
; Sample OEMINFO.INI
; 1/18/2000 BB
; This file contains manufacturer, model and support information
; that is displayed in the system control panel.
; Manufacturer and Model are displayed on System.General page
; Manufacturer is a required field
[general]
;Be carefully not to leave any trailing spaces after your manufacturer name!
Manufacturer=Fujitsu Siemens Computers
Model=Lifebook C1020
SupportURL=http://www.fujitsu-siemens.com/service
; The [OEMSpecific] keys are not displayed,
; but may be used by the OEM for system-specific information.
[OEMSpecific]
;SubModel=456A0123 ;optional additional oem info
;SerialNo=12345678 ;etc.
;OEM1=Your private info ;etc.
;OEM2=More private info ;etc.
; Support Info displayed when "Support Information..." button selected
[Support Information]
Line1="If you should have technical questions or problems in"
Line2="conjunction with your new personal computer, please get"
Line3="in touch with us. Please contact one of our IT Service"
Line4="Shops or your local sales office or our hotline:"
Line5=""
Line6="The telephone numbers and addresses can be found in the"
Line7="enclosed manuals:"
Line8=" * Safety, Guarantee and Ergonomics"
Line9=" * Service address booklet"
Hope the above is useful!