surprise: AutoHotKey + AutoHotKey_L works too on 64bit win. I tested it on win7.
The developer speaks from a increased performance by using the 64bit ahk build ( Xp Vista W7 )
Use an download from the header line or download the exe and rename it simular to your .ahk file. ( → 1-.exe, s.exe or s-.exe )
If you intent to create your own scripts compare the downloaded .exe with the newest build → autohotkey.net/~Lexikos/AutoHotkey_L
* 64.ahk is the renamed 1.ahk -_- 64.exe is the latest AHK_L.exe for 64bit os