Im beginner in LINUX and having windows os laptop.Tell me the best linux IDE for windows 64 bit.

You can try Putty tool for accessing your Linux Environment.This is a freeware easily available through internet.

Can you tell me the link for PUTTY TOOL(Windows 7 64bit)

A Linux IDE for Windows? Do you mean an IDE that can run on Windows and Linux? Develop Linux apps on Windows? What?

As far as I'm concerned, the best common IDE for Windows and Linux is Eclipse. If you want a Linux-like environment for Windows, install Cygwin (you can run Eclipse there also). If you want a real Linux system running with Windows, then install a virtual machine manager such as VirtualBox and Linux in a virtual machine. Then, run Eclipse or some of the other Linux IDE's there.

What is the difference b/w IDE and Virtual Machine?

Can you give me the link for linux virtualbox.My system os is Windows7(64bits)

An IDE and virtual machine are not related at all so i don't know why you are confused.
An IDE just gives you the capabilities of editing, creating, compiling, debugging, etc in a single application
Virtual Machine is used to run another OS(guest OS) in your main OS(host OS).
So, be clear what you want.

https://www.virtualbox.org/
An IDE is a programming tool/environment such as Visual Studio, Eclipse, Code::Blocks, etc.
A virtual machine is an emulated computer that runs as a guest in your own system.