angel1604lts@angel1604lts-HP-ProBook-4540s:~$ sudo strings /sys/firmware/acpi/tables/DSDT | grep -i windows
[sudo] password di angel1604lts:
Windows 2001
Windows 2001 SP1
Windows 2001 SP2
Windows 2001.1
Windows 2006
Windows 2009
Windows 2012
Windows 2013
Microsoft Windows
Microsoft WindowsME: Millennium Edition
Microsoft Windows NT
Windows 2001
Windows 2001 SP1
Windows 2001 SP2
Windows 2006
Windows 2009
Windows 2012
Windows 2013
Windows 2012
Windows 2012
Windows 2009
Windows 2009
Windows 2009
Windows 2009
angel1604lts@angel1604lts-HP-ProBook-4540s:~$