




 
The function 
software-version
 returns a string giving the version of the Operating System, or 
nil
 if this cannot be determined.
On MS Windows systems, 
description
 begins with the specific Operating System. This is 
"Windows 95"
, 
"Windows 98"
, 
"Windows Millennium"
, 
"Windows 2000"
, 
"Windows NT"
 or 
"Windows"
 (the latter if it is not one of the previous five). This is followed by the version numbers (Major.Minor), build and optionally service pack.
(software-version)
=>
"Windows NT: 4.0 (build 1381) Service Pack 6"
(software-version)
=>
"Windows Millennium: 4.90 (build 3000)"