From LQWiki

To view your files on an ext2 partition from Windows, use http://www.fs-driver.org/download.html's read-only mode.

Note that newer versions of ext3 use 256 byte inodes by default, which makes them unreadable with Extfs (at least to version c). Make ext3 filesystems with the -i 128 flag to retain compatibility. Other Windows software such as Acronis backup are also affected.

Another option is to use colinux which runs under Windows and allows you to mount any Linux filesystem.