This how-to uses the Subversion command-line client, PuTTYGen (you'll be generating a key and placing that on the server), Plink, and Pageant on Windows XP (32 or 64-bit).
I know that this looks like a lot to do, but it's quick, and mostly painless.

1. Select the 'Windows Binaries' link from Subversion's main website.
2. Select the 'Apache2.2' link.
3. Select the link who's description most closely matches 'Windows installer with the basic win32 binaries'. It should be the first link.
4. Run the installer.

1. Google for putty and go to their main site.
2. Select the 'Download' link from the menu at the top.
3. Select the link under the title 'A Windows installer for everything except PuTTYtel'.
4. Run the installer.

1. Open PuTTYGen.
2. Click 'Generate'.
3. Move your mouse around in the box to generate randomness. This creates two parts - the public key and the private key.
4. You might want to give the key a passphrase.
5. Click 'Save private key'. The location and name of this key for this tutorial is c:\test.ppk.
6. Do not close PuTTYGen.

1. SSH into your server and edit the file ~/.ssh/authorized_keys
2. Right-click on the generated public key in PuTTYGen and choose 'Select All'.
3. Right-click on the generated public key in PuTTYGen and choose 'Copy'.
4. Paste the clipboard contents onto the end of the authorized_keys file.
5. You can close PuTTYGen now and log out of your server.

1. You'll need to find the 'config' file. It's likely in the '%appdata%\Subversion' folder. Just open explorer and enter '%appdata%\Subversion' in the location bar.
2. Add the line 'ssh = C:/Program Files (x86)/PuTTY/plink.exe -i c:/test.ppk' under the section tunnels.

1. Make sure Pageant is running, and that you have added the generated private key. You will need to provide the passphrase here if you supplied one earlier.
2. Use the command 'svn co svn+ssh://user@server/repo' and it should work.