Platform virtualization, which separates an operating system from the underlying platform resources
There are plenty of virtual destros of linux too but frist of all we will have a look on Windows virtaul PC 2007 which is provided by microsoft.
In this we can run other opertaing system under running and working operating system
With Microsoft® Virtual PC 2007, you can create and run one or more virtual machines, each with its own operating system, on a single computer. This provides you with the flexibility to use different operating systems on one physical computer.
Download Virtaul pc 2007 ----------> http://www.microsoft.com/downloads/details.aspx?FamilyId=04D26402-3199-48A3-AFA2-2DC0B40A73B6&displaylang=en
visit this offical page of Microsoft :)
read the requirement lines instructions article and compartibility stuff need for run this and download according to ur present machine like 32 bit or 64 bit :)
its very easy and simple or mast to use :)
now some other virtual sentances but damn sexy and useful u will love them if u seriously try them :)
VMware Player is probably the simplest choice for most people. The Player allows you to run existing, pre-configured virtual machines or install new ones, albeit with some limitations regarding the configurations of the guest operating systems. For example, you will not be able to install guest add-ons, known as VMware Tools, which improve the overall performance of the guest operating systems.
Download --------->http://www.vmware.com/products/player/ :P
VMware Server is a stripped down version of the expensive yet highly worthy VMware Workstation. It contains the VMware Player - and then some, making it a more logical choice for installation.
However, to fully utilize its powers, you will have to be able to install it yourself, not exactly a difficult but neither a trivial task. Additionally, you will have to able to install the VMware Tools in guest operating systems, and possibly configure advanced options to improve the integrations between the host and the guest. The Tools will allow you to seamlessly move between the real and virtual operating systems, improve the mouse and monitor performance, allow you to synchronize the clock in guest machines, and more.
If you are willing to spend the extra time, it's definitely worth it. You'll enjoy the most complete virtualization package you can have for free.
Download---------> http://www.vmware.com/products/server/ :
VirtualBox wins somewhere in between the Player and the Server. It's much lighter and faster than either, but it's networking stack is the most difficult to configure for complex situations where the guest operating systems need to talk to one another or run services.
It has the unlimited snapshots feature, a highly valued option for people who need to frequently test multiple configurations of an operating system (or part thereof). The 3D support is similar to VMware Server. While neither will let you run real 3D tasks, the VirtualBox will give you a slight performance edge with older Windows games.
Download-------------> http://www.virtualbox.org/ :P
QEMU is probably the most difficult product to master and use. It's minimalist, entirely command line and will require good knowledge of the hardware infrastructure to setup properly. Still, it's something that you might want to consider, especially since you can find lots of ready operating system images on the Internet, including the official site.
Download-----------------> http://www.qemu.org/ :D
MojoPac is a very handsome and useful solution for Windows XP users. It allows you to run a virtualized version of your own installation, with full 3D support, making it ideal for games and programs that require the use of the graphic card and yet you cannot install where you might need them (workplace, Internet cafe).
MojoPac is limited in being a self-virtualization, but it's extremely simple to use. You do not need to worry about the network stack or drivers configurations.
What more, luckily, VirtualBox can be installed inside Mojo, allowing you to test and use other operating systems. It must be said that VirtualBox is the only virtualization product of three 'best choices' that can run from MojoPac.
and there are many other destros and virtuals like open vz, pay ware and all :) u can google dem and ask me if need any one :)
this is not 100 % copy paste material :D lol
50% is copy paste bcoz i dnt have time to rite whole by my own hands :D
and ya if u are really serious dan once visit the links i have given these are official site u will get full version free of cost if u facing prib in getting ful version drop ur problem here only i will get it for u...
read the work of these applications u will love it for sure but only and only if u read it
reading is virtue :P if have any prob can ask me any time :P