To access ReiserFS partitions under Windows, there are two tools available. The first is rfstool (a user-space application that can be used to copy files over to your Windows partition).
The better option is ReiserDriver, which is a file system driver that allows ReiserFS drives to be read natively. (Of course, I'm a bit biased, seeing as I wrote it.) The ReiserFS partitions will show up as additional drives to Windows. It's very similar to ext2fsd, which was mentioned above.
Try it out at
rfsd.sf.net