Method:

1) Go to run or simply press win+r . Type regedit and enter regisrtry.
2) Expand--->HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion.
3) Under CurrentVersion search for the key OEMInformation. If it doesnt exist then create
it.
4) Then to the right side of the panel create new strings. To create new string, right click on right panel , then new---> string.

Create these strings-
Manufacture
Logo
Model
SupportPhone
SupportHours
SupportURL

5) Then right click on created string and select modify.

6) Then modify their values as-

Manufacture - Any desired name. (eg: Raj Dhakate)
Model - Your Computer model. (eg: HCL P28 PDC)
SupportHours - Any Desired. (eg: 24x7 hrs)
SupportPhone - Any number.
SupportURL - Any desired URL. (eg: www.sevenforums.com)
Logo - Full path of the image. (eg: C:\Users\Raj\My Documents\OEMlogo.bmp or where you have saved the image)

7) For Logo, you should have a 96x96 resized image in .bmp format.

8) Then right click on Computer Icon on the desktop and click Properties. You will now see your customized Properties Window.
Attachment 79223

Attached Thumbnails