How to mount a Linux EXT2FS drive in Windows - http://sourceforge.net/projects/ext2fsd/
A dual boot is usually set up by installing windows and Linux operating systems on different partitions of your hard disk. The windows partition can easily be accessed from linux, by mounting it using the standard linux mount utilities. I have been looking for something similar on windows, which would enable me to mount my Linux partition under windows. Found these ext2fsd drivers on http://sourceforge.net/projects/ext2fsd ... they seem to be pretty good.
Just download the drivers, unzip, run setup->setup.bat to mount your drive , use the mount utility from the same site, and execute
"mount.exe drive_number partition_number drive_letter" from the command prompt
eg. "mount 0 4 g:"= to mount the 4th partition of your 1st(0th) physical hard disk onto the g: drive. you can unmount using the same utility "mount /umount g:"
-- AmitShanbhag
Another alternative is to actually have linux running within windows when you need it, using something like CoLinux, or commercial products such as VmWare or MsVirtualPc. This gives you access to any of the other filesystems that linux supports, such as reiserfs, xfs, ext3, etc.
A detailed tutorial on getting this done can be found at http://www.amitshanbhag.com/mediawiki/index.php/MountLinuxPartition
From Google it leads to links which claim MicrosoftServicesForUnix can interoperate with EXT2FS partitions. Probably someone else here can comment on caveats and limitations.