Did you run the .exe file ?
There is a manaul in not so good english, with the synth.
Installation
A case to use for the first time
You carry out setting initialization tool "initsettings.exe" in the directory same as this file. Then setting is initialized.
The VSTi DLL is called “Synth1 VST.dll”. Copy this file to the VST plugin folder of the host application.
For example, if your favourite sequencer is Cubase , you should copy "Synth1 VST.dll" to "C:\Program Files\Cubase SX\Vstplugins" directory.
Installation is now complete. Please confirm that Synth1 appears in the plugin menu of the host application.
At the time of version up (When you have already used Synth1 and want to succeed setting information)
Please execute the set succession tool (reg2ini.exe) that exists in the same directory as this file, and generate the configuration file (ini file) when improving from the version before Synth1 V1.11.
Please overwrite-copy plugin file "Synth1 VST.dll" by manual operation to a VST plugin folder.
Installation is now complete.