Here you will find various SayIt Launch Issues and Troubleshooting Tips
SayIt Launches with the wrong program or just opens a command window and closes
If when trying to launch SayIt, a different application opens ie: Windows Media Player, or you run the jnlp and just get a command window flash open and close, you may need to reset the file association for jnlp files;
Make sure Java is installed
Right click on the SayIt jnlp and click Open With...
Click Browse
Go to C:\Program Files(x86)\Java\bin (OR C:\Program Files\Java/bin if x64) and choose javaws
SayIt should open as normal