Detecting if SP2 is installed on Windows XP

hi

 i have a specific requirement of detecting if SP2 is installed on a Windows XP machine over browsers. Is there a mechanism of doing that?

i have explored Request.Browser.Platform and Request.UserAgent but these stop at telling the major Operating system e.g. Windows XP or Windows Vista.

it seems there may be a convoluted way to figuring this out..

cheers

abhishek
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