Someone asked me how they could tell which build of Windows 7 there were on, as they “inherited” a machine from a colleague and weren’t sure if they were still on beta, RC or RTM.
You can find out via the registry, so click the orb in the bottom left of the screen, type “regedit” and press return. Use the navigation tree on the left to find HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion.
In the right hand panel you’ll see a long list of values, one of which is “CurrentBuildNumber”.
If this is 7600 then you’re on the RTM (release to manufacturing) version. 7100 or 7200 means you’re on the RC (Release Candidate) – this will stop working by June 2010 so you should be planning to move to the RTM version.
Anything earlier means you’re in never-never land.