The current public release version is 12.0027

You can check which version you're currently running by looking in the main Herschel window:

To upgrade Herschel follow this checklist:

1 Download the upgrade program using this link.
2 Use Windows File Explorer to confirm where you installed Herschel.  It's usually the folder \HERSCHEL_V12 or \HMSV11.  
3 Make sure nobody is logged into Herschel.
4 Run the upgrade program Herschel_V12_Upgrade.exe and follow the on-screen instructions to install the new version into your Herschel folder.
5 Once the upgrade is complete, open Herschel and check the version number is correct.  If it's not, you've probably installed the upgrade into the wrong folder.
6 Once you've completed the upgrade, you can tell users they can log back into Herschel.  
7  Double-clicking the version box in the main Herschel window will display a list of the changes contained in the upgrade.