ModSecurity 2.5.11 was released on November 6, 2009. And so, here is the 64 bit binary for Windows. It also includes latest version of libxml2 (version 2.7.6).
For installation instructions, refer to the ‘install.txt’ file in the zip archive.
Download:
modsecurity-apache_2.5.11-x64.zip
CRC32: 231399B8
MD5: 6145769A5AB033AE97A7C2E7603A2F57
SHA1: D84F88289FAC06A77ABFDEA4322C85A277A60963