How to determine the operating system from the build box

[teognost]

I would like to send an email at the end of build process -specifying OS from the build box.
I looked into Macros and I found OS env variable but unfortunately the info stored here is not complete-it says Windows_NT but I would like to see it as it appears when right clicking in My Computer (e.g. Microsoft Windows 2003 Standard Edition Service Pack1).
Can this be acheived using VBP?