The windows app allowing it to see linux partitions is ext2fsd
Even though it says ext2 it can allow mount and read ext3. Not sure about writing but I think it's supported and does it quite well.
Just install it, and then open a command prompt, cd to the directory you installed it, and run mount 0 2 e:
0 = Hard drive number
1 = Partition number
e: = Drive letter to mount to