If you are using Windows XP - right click on "My Computer" and choose (left click) Properties from the drop down menu.
platform
The operating system is immaterial. It is the languages used that are important. If you are targeting a specific platform then it obviously makes sense to develop upon that platform, but for cross-platform programming it really makes no difference what operating system you use.
I guess windows 7 is the latest version of operating system in MICROSOFT.
Yes, each version of "Windows" is an operating system.
Platform
Android
An operating system provide an interface between the user and hardware. operating system is a platform in which all the user applications can run
The platform.
Platform
sometimes is called a platform
Do you mean Windows? It's the most popular and compatible operating system available from Microsoft.
Java is distributed for different "platforms", where a platform is basically a processor / operating system combination. You need to know what operating system you are using, and download the corresponding Java version. I believe the Vaio comes with Microsoft Windows, so the only thing you need to figure out is whether you have the 64-bit version, or an older, 32-bit version. Then go to the Java site and download the corresponding version.