How to install/upgrade to latest Warcraft 3 Patch online using Battle.net Guide. Whenever Blizzard releases new patch, It becomes available on all the official Battle.net realms of Blizzard. You can easily upgrade yourself to the latest patch by connecting Battle.net, it automatically downloads & install the update.
• Original Warcraft 3 The Frozen Throne Copy/CD-Key (If you don't have it, download the offline patch upgrade file from Blizzard's FTP site)
• Internet Connection (Broadband).
• Start your Warcraft 3 TFT.
• Click Battle.net, select a realm and connect.
• A download status window will pop-up, let it download the update..
• After the download completes another window will pop-up asking for confirmation to restart your Warcraft 3, Click restart!
• You Warcraft 3 will be restarted and you will be patched to Warcraft 1.25 Patch.
• See the version number at right bottom of Warcraft 3 to validate if you have the latest patch.
• Enjoy :)
Update: Follow this guide, if you are having "Registry error loading key 'Warcraft III\InstallPath' Error"
PS: If you are having any problems while installing the patch updates from Blizzard. Just post a comment :)