WebDAV and Windows

I'm having a lot of trouble trying to get WebDAV (using apache2 on
debian) and windows (mostly XP, some W2K, and one XP64) to play nicely
together. Ideally, I'd like to let windows clients map drive letters to
the webdav server directly. I gather from googling a bit that there is
some problem with windows refusing to send plain text passwords to the
webdav server over http. At the moment, I have had some success using
"netdrive.exe" - but I am unhappy about using an orphaned binary-only
program (and it doesn't work on XP64).

Does anyone have any suggestions for a reliable method that will work
with different windows clients *without* third-party software (or at
least, with only open-source third-party software)? I can easily change
things at the server end - I'm using apache2 since I'm familiar with it,
but I've no problems using something else as a webdav server.

mvh.,

David