Here is the step by step procedure to upgrade your wallet from 2.4.2 to 2.5.0 under Windows:0. Download the new client (version 2.5.0) here
https://github.com/shiftcurrency/shift/releases/tag/2.5.0.
1. In order to execute this procedure, you need to be in a command prompt window. If you aren't yet, navigate through the Windows explorer to your new Gshift executable, hold the Shift key on the keyboard and right-click on a blank space. Release the Shift key. In the contextual menu, click on Open command window here.
The command prompt window is now opened directly in the folder of the executable.
2. Type the command 'gshift-windows-amd64 removedb' (without the quotes and followed by Enter). You will be prompted to confirm your choice to remove the database, enter 'y' to confirm (without the quotes, and followed by Enter).
Your old database has now been removed.
3. Start the client with the command 'gshift-windows-amd64' (without the quotes and followed by Enter) and wait for the blockchain to sync up. You're done!