Ext2Fsd (Ext2 File System Driver for Windows) is an open source Linux ext2/ext3 file system driver created for Windows systems.
Ext2fsd is much stable for normal works, with writing access enabled. I use it on my own computer all along. The performance comes to be an issue when theres heavy I/O operations. Thats the thing to do next step.
If you really need very heave writing i/O jobs, I strongly recommend you to create an ext2 partition as a swap between windows and linux systems.

Features Ext2Fsd supports:
1. ext2/ext3 volume reading & writing
2. ext3 journal replay when mounting
3. various codepage: utf8, cp936, cp950
4. mountpoint automatical assignment
5. large inode size: 128, 256,
6. large file size bigger than 4G
7. OS: 2k, xp, vista, server 2008 (i386/amd64)

Features Ext2Fsd doesn't support:
1. ext3 journal support
2. htree for directory entry management
3. ext4 extent support
4. LVM and Linux raid (md)
5. NT4 is no longer supported.
6. Win7 or server 2008 r2 support are uncertain.

The license of this software is Free, you can free download and free use this disk management software.