How to get OS version from Logon script

Hi ,

We are in need to create a logon script , where we should identify the OS version & proceed.

We have a mix of XP/Win7/Win2k8/Win2k8R2/Win2k3/Win2k12)

1) We have tried using "Systeminfo" but this takes 10 secs of time to run.

2) We have tried ver , but ver will give same ver number for Win7 & Wink8R2.

3) Using wmi , wmi might not be installed on XP PCs.

Can any one please suggest a way!!

Appreciate your kind help - Thanks :)

Sai Krishna