Valid registry key.

[GEOSoft]

Returns the valid (short) registry key dependent on CPU architecture. You can send it all or part of the key and it shouldn't be AutoIt version dependent. If you pass it an invalid key (HKZU) then it will return an error.

;
MsgBox(0, "Test Results", _RegKey("HKEY_LOCAL_MACHINE64\SOFTWARE\Microsoft\"))
MsgBox(0, "Test Results", _RegKey("HKLM\SOFTWARE\Microsoft\"))

Func _RegKey($sKey)
   Local $sHold = ""
   If StringInStr($sKey, "\") Then
      $sHold = StringMid($sKey, StringInStr($sKey, "\"))
      $sKey = StringLeft($sKey, StringInStr($sKey, "\")-1)
   EndIf
   $sKey = StringReplace ($sKey, "64", "")
   $sKey = StringRegExpReplace($sKey, "(?i)^\b(HK)ey_(L|U|C)(?:.*_)?(M|U|C|R)?.*", "$1$2$3")
  ;If NOT StringRegExp($sKey, "(?i)hklm|hkcu|hkcr|hkcc|hku") Then Return SetError(1,0, $sKey & " is not a valid key name")
   If NOT StringRegExp($sKey, "(?i)hklm|hkcu|hkcr|hkcc|hku") Then Return SetError(1,0, $sKey & "")
   If @OSArch = "X64" Then $sKey &= "64"
   Return StringUpper($sKey) & $sHold
EndFunc
;

Enjoy

EDIT:

If anyone has a problem with this function please let me know and include your AutoIt version when you reply.

Tested on 3.2.13.13 and 3.3.0.0

EDIT 2:

Modified the error return to set error level to 1 and return a blank string so you can use

$Reg= _RegKey("HKEY_LOCAL_MACHINE64\SOFTWARE\Microsoft\")
If $Reg Then MsgBox(0, "Test Results", $Reg)

Edited January 2, 2009 by GEOSoft

[GEOSoft]

Updated to a different error return. See post #1

Remember that the primary use is to return the short value of the registry hive/key and append the "64" to it if required for X64 systems.

[FireFox]

@GeoSoft

hm... its a good idea

Cheers, FireFox.