There are many people who would like to install and use Linux operating system. But these people find the installation process very difficult. Many a times replacing your old windows operating system is also out of question. This is the main reason why people are scared to wipe out windows completely and try out Linux. What these people would like instead is an application which can be installed as a normal windows operation and could be uninstalled easily should the need arise. To satisfy the needs of those who find it difficult to install Linux, there is new utility called 
Wubi runs as a windows application allowing you to install Linux. You just need to choose few options and then you are through. First Select the drive on which you want to install Ubuntu (there is no need to repartition your hard disk). Then select the the installation size. Yo also have a choice of installing from different flavors of Ubuntu viz. Ubuntu,Kubuntu, Xubuntu and Mythbuntu. You have a choice of language selection. English is the default language. Then you have to enter a username and password of your choice for the Ubuntu Linux. After the installation is complete you get an option to boot into your Ubuntu Linux by selecting an option in your windows boot menu.
To run Wubi effectively you need 256 MB of RAM, 5 GB harddisk space. Wubi runs on following platforms:- Windows 98, 2000, XP, Vista
Wubi just like Ubuntu costs absolutely nothing and is free from spyware and malware. You may download Wubi from the following download link.