Code:
Set SNSet = GetObject("winmgmts:").InstancesOf _
("Win32_OperatingSystem")
For Each SN In SNSet
MsgBox "The serial number for the installed OS is: " & _
SN.SerialNumber
Next
Paste that into a notepad, name it anything you want with a *.vbs extension and then you can click to find out the serial number of your OS.
** NOTE ** The serial number is NOT the same as your CD KEY. Tested and works on an XP system.
Got a useless piece of VBS... post it here.
__________________
<code>
(\ /) This is Bunny. Add him to your signature
(O.o) to help him achieve <a href=\"http://carboxymoron.com/sigbunny/\" title=\"the signature bunny\">world domination</a>.
(> <)
</code>
<code>Shakie<br>Smodministrator<br>
\"If I don\'t step over the line every now-and-then, how will I know where it is?\"</code>
Some useless VBS for ya... 
Linear Mode
