If you have Windows and Linux in the same machine and want to access files of your Linux partition from Windows then you need to use some kind of software to read Ext file system because Windows can't access Ext file system without any additional utility. So you can access Ext 2/3/4 partitions with these three utilities which are completely free: Ext2Fsd (Ability to Read/Write on Ext file system), Linux Reader (Only can read Ext file system to avoid any problem in Ext partition), Ext2Read (Can read Ext file system).
