How to make Warcraft 3 Registry Entries:
1. Open up regedit (start > run > regedit)
2. Go to HKEY_CURRENT_USER\SOFTWARE\Blizzard Entertainment\
3. Create new key, name it 'Warcraft III' (without quotes)
4. On right side of new key entry, right click and create new string value
5. Name it 'InstallPath' (without quotes)
6. Change the value of InstallPath to wherever you installed it (example: 'c:\warcraft 3\')
7. Reinstall Warcraft 1.24d Patch. (this time your war3 will be installed without any errors)
8. Enjoy! your Warcraft is patched to 1.26a