How to incrementally backup whole HDD to external from Windows?

"Freebyte backup does incremental backups and is free software.

Freebyte Backup is a freeware backup
program for Windows. It allows one to
easily copy (and filter) a large
number of files and directories from
various sources into one backup
directory. It is possible to backup
all files found in the specified set
of input directories, or to have only
certain file types copied. Files can
be filtered according to
file-extensions. E.g. you can specify
that you want to backup all .doc,
.rtf, .jpg, .bmp files, but none of
the .exe, .dll and .txt files. You can
also very easily define new file
extensions inside the filter.

Incremental backup options With the
optional 'Incremental backup' feature,
the program only copies files which
have not yet been saved by Freebyte
Backup. It is also possible to specify
a date, so that only files
changes/created after a certain
date/time are copied, or to only copy
files if they are more recent than the
corresponding files at the target
location."

"It looks like you're needing something like Clonezilla (http://clonezilladotorg/). It doesn't perform an incremental backup like you had mentioned wanting, but I haven't seen any other imaging software that actually only copies incremental files.

Also, if you were needing an incremental backup solution for the ext3 partition from Windows, you'll of course need to be able to access the partition with something like http://www.fs-driverdotorg/index.html or http://www.chrysocome.net/explore2fs. After that, you should be able to do incremental backups with SyncBack SE (http://www.2brightsparks.com/freeware/). I'm not sure of a way to access the swap partition though unless explore2fs or the ext2 driver for Windows allows that as well."