There are so many applications which will allow you to use linux on Windows such as VMWARE , Virtual Box etc. Or there is some emulator kind of software’s which will allow you to run Linux on Windows.
One such application today what I am going to discuss is wubi it’s just like a software we can install and it will install linux on your system without modification of your partitions/partition table. Its as simple as pressing next, next, next and then just restart the system, you will find Ubuntu and Windows on your system and start up screen as a duel boot. This is some thing like virtual machine. And some other similar applications are.
www.cygwin.com
www.mingw.org
www.colinux.org