Ya, i have the same error, i tried your way but it didnt work error is
Blizzard PrePatch v2.70 compiled on Jul 7 2003
This program patches Warcraft 3
Log created at 5:49 pm on 09/22/2005
Registry error loading key 'Warcraft III\InstallPath'
The system cannot find the file specified.
RESULT: Prepatch failed
But my WC3 is in D drive
Blizzard PrePatch v2.70 compiled on Jul 7 2003
This program patches Warcraft 3
Log created at 5:49 pm on 09/22/2005
Registry error loading key 'Warcraft III\InstallPath'
The system cannot find the file specified.
RESULT: Prepatch failed
But my WC3 is in D drive