Can I use JavaScript to check for installed software on a client machine?

Is there 开发者_运维问答any way to check the installed software on a client machine using JavaScript?

For example: I want to check on the client machine whether the 'Epson JavaPOS ADK' is installed or not.

You cannot do that using Javascript, you don't have access to the local file system.

Impossible

Due to security issues.

But you may still be able to detect any installed software if it installs any browser accessible ActiveX controls. So if you'd try to create an instance of it and see of you actually get an instance of it it has the software. But this is totally software dependent.

That would be extremely dangerous for the client so, no. You can't check nor access the file system. Nor with JavaScript, nor with Java Applets nor with Flash.