The ncdns-nsis project, which provides a zero-configuration Windows installer
for Namecoin domain name resolution functionality, has merged SPV support,
implemented via BitcoinJ. This enables Windows machines to resolve
domain names without having to download the full Namecoin chain.
Merging this functionality means that Namecoin domain names can be resolved on Windows client machines with only a minimal chain synchronization and storage burden, in exchange for a limited reduction in the security level provided.
Installer binaries will be published in due course as remaining ncdns-nsis issues are concluded.
To use the BitcoinJ client, run the ncdns-nsis installer and select the SPV
option when asked whether to install a Namecoin node. Run BitcoinJ after
installation and wait for synchronization to complete;
.bit name resolution
is then available.