Inspired by I2P-Zero ( https://github.com/knaccc/i2p-zero ) I built a zero-dependency windows installer. This means you do not need to have java installed to run i2p - the installer comes with everything it needs, in just 33 MB
Give it a try at http://188.172.154.147/installer-0.9.38.exe and let me know if you run into any issues. The source code is in the "i2p.jlink" and "i2p.wininst" branches in monotone.
zab