open notepad dump the following lines into it and save it with the name OEMINFO.INI in the c:\windows\system32 directory:

[General]
Manufacturer=Your Name Here
Model=Your Model Here
[Support Information]
Line1=Your Name Here
Line2=Your Address Here
Line3=Your Email Address Here


Save the file, then make a right click on my computer select properties, in the general tab a button will be highlighted (support information) make a click on it, you will be able to see the changes.
Now if you want to display some more information then simply increase the line in the file.
ex: Line4=Your Working Hours Here