Windows Registry Access

The following procedure demonstrates how Registry information can be altered by disabling and re-enabling the Autorun/Autoplay for the current user. It then reads the Registry to list some of the programs that auto start for all users.

Code courtesy of Michael Calkins WARNING! Use care when editing or altering Registry settings! YOU will be responsible for any damages incurred!

' winreg.h
CONST HKEY_CLASSES_ROOT = &H80000000~&
CONST HKEY_CURRENT_USER = &H80000001~&
CONST HKEY_LOCAL_MACHINE = &H80000002~&
CONST HKEY_USERS = &H80000003~&
CONST HKEY_PERFORMANCE_DATA = &H80000004~&
CONST HKEY_CURRENT_CONFIG = &H80000005~&
CONST HKEY_DYN_DATA = &H80000006~&
CONST REG_OPTION_VOLATILE = 1
CONST REG_OPTION_NON_VOLATILE = 0
CONST REG_CREATED_NEW_KEY = 1
CONST REG_OPENED_EXISTING_KEY = 2

' http://msdn.microsoft.com/en-us/library/ms724884(v=VS.85).aspx
CONST REG_NONE = 0
CONST REG_SZ = 1
CONST REG_EXPAND_SZ = 2
CONST REG_BINARY = 3
CONST REG_DWORD_LITTLE_ENDIAN = 4  '   value is defined REG_DWORD in Windows header files
CONST REG_DWORD = 4 '                  32-bit number
CONST REG_DWORD_BIG_ENDIAN = 5 '       some UNIX systems support big-endian architectures
CONST REG_LINK = 6
CONST REG_MULTI_SZ = 7
CONST REG_RESOURCE_LIST = 8
CONST REG_FULL_RESOURCE_DESCRIPTOR = 9
CONST REG_RESOURCE_REQUIREMENTS_LIST = 10
CONST REG_QWORD_LITTLE_ENDIAN = 11  '  64-bit number in little-endian format
CONST REG_QWORD = 11 '                 64-bit number
CONST REG_NOTIFY_CHANGE_NAME = 1
CONST REG_NOTIFY_CHANGE_ATTRIBUTES = 2
CONST REG_NOTIFY_CHANGE_LAST_SET = 4
CONST REG_NOTIFY_CHANGE_SECURITY = 8

' http://msdn.microsoft.com/en-us/library/ms724878(v=VS.85).aspx
CONST KEY_ALL_ACCESS = &HF003F&
CONST KEY_CREATE_LINK = &H0020&
CONST KEY_CREATE_SUB_KEY = &H0004&
CONST KEY_ENUMERATE_SUB_KEYS = &H0008&
CONST KEY_EXECUTE = &H20019&
CONST KEY_NOTIFY = &H0010&
CONST KEY_QUERY_VALUE = &H0001&
CONST KEY_READ = &H20019&
CONST KEY_SET_VALUE = &H0002&
CONST KEY_WOW64_32KEY = &H0200&
CONST KEY_WOW64_64KEY = &H0100&
CONST KEY_WRITE = &H20006&

' winerror.h
' http://msdn.microsoft.com/en-us/library/ms681382(v=VS.85).aspx
CONST ERROR_SUCCESS = 0
CONST ERROR_FILE_NOT_FOUND = &H2&
CONST ERROR_INVALID_HANDLE = &H6&
CONST ERROR_MORE_DATA = &HEA&
CONST ERROR_NO_MORE_ITEMS = &H103&
'---------------------------------------------------------------------------------------------
' REGSAM is an ACCESS_MASK (winreg.h), which is a DWORD (winnt.h)

DECLARE DYNAMIC LIBRARY "advapi32"

 ' http://msdn.microsoft.com/en-us/library/ms724897(v=VS.85).aspx
 FUNCTION RegOpenKeyExA& (BYVAL hKey AS _OFFSET, BYVAL lpSubKey AS _OFFSET, BYVAL ulOptions AS _UNSIGNED LONG, BYVAL samDesired AS _UNSIGNED LONG, BYVAL phkResult AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724837(v=VS.85).aspx
 FUNCTION RegCloseKey& (BYVAL hKey AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724865(v=VS.85).aspx
 FUNCTION RegEnumValueA& (BYVAL hKey AS _OFFSET, BYVAL dwIndex AS _UNSIGNED LONG, BYVAL lpValueName AS _OFFSET, BYVAL lpcchValueName AS _OFFSET, BYVAL lpReserved AS _OFFSET, BYVAL lpType AS _OFFSET, BYVAL lpData AS _OFFSET, BYVAL lpcbData AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724911(v=VS.85).aspx
 FUNCTION RegQueryValueExA& (BYVAL hKey AS _OFFSET, BYVAL lpValueName AS _OFFSET, BYVAL lpReserved AS _OFFSET, BYVAL lpType AS _OFFSET, BYVAL lpData AS _OFFSET, BYVAL lpcbData AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724923(v=VS.85).aspx
 FUNCTION RegSetValueExA& (BYVAL hKey AS _OFFSET, BYVAL lpValueName AS _OFFSET, BYVAL Reserved AS _UNSIGNED LONG, BYVAL dwType AS _UNSIGNED LONG, BYVAL lpData AS _OFFSET, BYVAL cbData AS _UNSIGNED LONG)

 'untested:

 ' http://msdn.microsoft.com/en-us/library/ms724862(v=VS.85).aspx
 FUNCTION RegEnumKeyExA& (BYVAL hKey AS _OFFSET, BYVAL dwIndex AS _UNSIGNED LONG, BYVAL lpName AS _OFFSET, BYVAL lpcName AS _OFFSET, BYVAL lpReserved AS _OFFSET, BYVAL lpClass AS _OFFSET, BYVAL lpcClass AS _OFFSET, BYVAL lpftLastWriteTime AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724844(v=VS.85).aspx
 FUNCTION RegCreateKeyExA& (BYVAL hKey AS _OFFSET, BYVAL lpSubKey AS _OFFSET, BYVAL Reserved AS _UNSIGNED LONG, BYVAL lpClass AS _OFFSET, BYVAL dwOptions AS _UNSIGNED LONG, BYVAL samDesired AS _UNSIGNED LONG, BYVAL lpSecurityAttributes AS _OFFSET, BYVAL phkResult AS _OFFSET, BYVAL lpdwDisposition AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724851(v=VS.85).aspx
 FUNCTION RegDeleteValueA& (BYVAL hKey AS _OFFSET, BYVAL lpValueName AS _OFFSET) '<<< DANGER

 ' http://msdn.microsoft.com/en-us/library/ms724845(v=VS.85).aspx
 FUNCTION RegDeleteKeyA& (BYVAL hKey AS _OFFSET, BYVAL lpSubKey AS _OFFSET) '<<< DANGER

 ' http://msdn.microsoft.com/en-us/library/ms724905(v=VS.85).aspx
 FUNCTION RegQueryMultipleValuesA& (BYVAL hKey AS _OFFSET, BYVAL val_list AS _OFFSET, BYVAL num_vals AS _UNSIGNED LONG, BYVAL lpValueBuf AS _OFFSET, BYVAL ldwTotsize AS _OFFSET)

 ' http://msdn.microsoft.com/en-us/library/ms724902(v=VS.85).aspx
 FUNCTION RegQueryInfoKeyA& (BYVAL hKey AS _OFFSET, BYVAL lpClass AS _OFFSET, BYVAL lpcClass AS _OFFSET, BYVAL lpReserved AS _OFFSET, BYVAL lpcSubKeys AS _OFFSET, BYVAL lpcMaxSubKeyLen AS _OFFSET, BYVAL lpcMaxClassLen AS _OFFSET, BYVAL lpcValues AS _OFFSET, BYVAL lpcMaxValueNameLen AS _OFFSET, BYVAL lpcMaxValueLen AS _OFFSET, BYVAL lpcbSecurityDescriptor AS _OFFSET, BYVAL lpftLastWriteTime AS _OFFSET)
END DECLARE

 ' http://msdn.microsoft.com/en-us/library/ms725490(v=VS.85).aspx
TYPE VALENT 'for RegQueryMultipleValues
 ve_valuename AS _OFFSET
 ve_valuelen AS _UNSIGNED LONG
 ve_valueptr AS _OFFSET
 ve_type AS _UNSIGNED LONG
END TYPE


' example:

DIM hKey AS _OFFSET
DIM Ky AS _OFFSET
DIM SubKey AS STRING
DIM Value AS STRING
DIM bData AS STRING
DIM t AS STRING
DIM dwType AS _UNSIGNED LONG
DIM numBytes AS _UNSIGNED LONG
DIM numTchars AS _UNSIGNED LONG
DIM l AS LONG
DIM dwIndex AS _UNSIGNED LONG

Ky = HKEY_CURRENT_USER
SubKey = "Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" + CHR$(0)
Value = "NoDriveTypeAutoRun" + CHR$(0)
bData = SPACE$(4)
numBytes = LEN(bData)

DO
 PRINT "This value enables/disables AutoRun/AutoPlay for the current user:"
 l = RegOpenKeyExA(Ky, _OFFSET(SubKey), 0, KEY_READ, _OFFSET(hKey))
 IF l THEN
  PRINT "RegOpenKeyExA failed. Error: 0x" + LCASE$(HEX$(l))
 ELSE
  l = RegQueryValueExA(hKey, _OFFSET(Value), 0, _OFFSET(dwType), _OFFSET(bData), _OFFSET(numBytes))
  IF l THEN
   PRINT "RegQueryValueExA failed. Error: 0x" + LCASE$(HEX$(l))
  ELSE
   PRINT whatKey$(Ky) + "\" + SubKey
   PRINT whatType(dwType) + " " + Value + " = " + formatData(dwType, numBytes, bData)
  END IF
  l = RegCloseKey(hKey)
  IF l THEN
   PRINT "RegCloseKey failed. Error: 0x" + LCASE$(HEX$(l))
   END
  END IF
 END IF
 IF dwType <> REG_DWORD THEN
  PRINT "Oops. I expected that value to be a DWORD."
  EXIT DO
 END IF
 PRINT
 PRINT "Would you like to change that value? ";
 DO
  _LIMIT 20
  t = LCASE$(INKEY$)
 LOOP UNTIL (t = "y") OR (t = "n")
 PRINT t
 IF t = "y" THEN
  PRINT "I recommend setting this value to 0xff to disable AutoRun for the current user."
  PRINT "Enter a new DWORD value: 0x";
  LINE INPUT t
  bData = MKL$(VAL("&h" + t + "&"))
  t = "y"
  l = RegOpenKeyExA(Ky, _OFFSET(SubKey), 0, KEY_ALL_ACCESS, _OFFSET(hKey))
  IF l THEN
   PRINT "RegOpenKeyExA failed. Error: 0x" + LCASE$(HEX$(l))
  ELSE
   l = RegSetValueExA(hKey, _OFFSET(Value), 0, dwType, _OFFSET(bData), numBytes)
   IF l THEN
    PRINT "RegSetValueExA failed. Error: 0x" + LCASE$(HEX$(l))
   END IF
   l = RegCloseKey(hKey)
   IF l THEN
    PRINT "RegCloseKey failed. Error: 0x" + LCASE$(HEX$(l))
    END
   END IF
  END IF
  PRINT
 END IF
LOOP UNTIL t = "n"

PRINT
PRINT "This key lists some of the programs that auto start for all users:"
Ky = HKEY_LOCAL_MACHINE
SubKey = "SOFTWARE\Microsoft\Windows\CurrentVersion\Run" + CHR$(0)
Value = SPACE$(261) 'ANSI Value name limit 260 chars + 1 null
bData = SPACE$(&H7FFF) 'arbitrary

l = RegOpenKeyExA(Ky, _OFFSET(SubKey), 0, KEY_READ, _OFFSET(hKey))
IF l THEN
 PRINT "RegOpenKeyExA failed. Error: 0x" + LCASE$(HEX$(l))
ELSE
 PRINT whatKey$(Ky) + "\" + SubKey
 dwIndex = 0
 DO
  SLEEP 1
  numBytes = LEN(bData)
  numTchars = LEN(Value)
  l = RegEnumValueA(hKey, dwIndex, _OFFSET(Value), _OFFSET(numTchars), 0, _OFFSET(dwType), _OFFSET(bData), _OFFSET(numBytes))
  IF l THEN
   IF l <> ERROR_NO_MORE_ITEMS THEN
    PRINT "RegEnumValueA failed. Error: 0x" + LCASE$(HEX$(l))
   END IF
   EXIT DO
  ELSE
   PRINT whatType(dwType) + " " + LEFT$(Value, numTchars) + " = " + formatData(dwType, numBytes, bData)
  END IF
  dwIndex = dwIndex + 1
 LOOP
 PRINT dwIndex; "Values."
 l = RegCloseKey(hKey)
 IF l THEN
  PRINT "RegCloseKey failed. Error: 0x" + LCASE$(HEX$(l))
  END
 END IF
END IF

END

FUNCTION whatType$ (dwType AS _UNSIGNED LONG)
SELECT CASE dwType
 CASE REG_SZ: whatType = "REG_SZ"
 CASE REG_EXPAND_SZ: whatType = "REG_EXPAND_SZ"
 CASE REG_BINARY: whatType = "REG_BINARY"
 CASE REG_DWORD: whatType = "REG_DWORD"
 CASE REG_DWORD_BIG_ENDIAN: whatType = "REG_DWORD_BIG_ENDIAN"
 CASE REG_LINK: whatType = "REG_LINK"
 CASE REG_MULTI_SZ: whatType = "REG_MULTI_SZ"
 CASE REG_RESOURCE_LIST: whatType = "REG_RESOURCE_LIST"
 CASE REG_FULL_RESOURCE_DESCRIPTOR: whatType = "REG_FULL_RESOURCE_DESCRIPTOR"
 CASE REG_RESOURCE_REQUIREMENTS_LIST: whatType = "REG_RESOURCE_REQUIREMENTS_LIST"
 CASE REG_QWORD: whatType = "REG_QWORD"
 CASE ELSE: whatType = "unknown"
END SELECT
END FUNCTION

FUNCTION whatKey$ (hKey AS _OFFSET)
SELECT CASE hKey
 CASE HKEY_CLASSES_ROOT: whatKey = "HKEY_CLASSES_ROOT"
 CASE HKEY_CURRENT_USER: whatKey = "HKEY_CURRENT_USER"
 CASE HKEY_LOCAL_MACHINE: whatKey = "HKEY_LOCAL_MACHINE"
 CASE HKEY_USERS: whatKey = "HKEY_USERS"
 CASE HKEY_PERFORMANCE_DATA: whatKey = "HKEY_PERFORMANCE_DATA"
 CASE HKEY_CURRENT_CONFIG: whatKey = "HKEY_CURRENT_CONFIG"
 CASE HKEY_DYN_DATA: whatKey = "HKEY_DYN_DATA"
END SELECT
END FUNCTION

FUNCTION formatData$ (dwType AS _UNSIGNED LONG, numBytes AS _UNSIGNED LONG, bData AS STRING)
DIM t AS STRING
DIM ul AS _UNSIGNED LONG
DIM b AS _UNSIGNED _BYTE
SELECT CASE dwType
 CASE REG_SZ, REG_EXPAND_SZ, REG_MULTI_SZ
  formatData = LEFT$(bData, numBytes)
 CASE REG_DWORD
  t = LCASE$(HEX$(CVL(LEFT$(bData, 4))))
  formatData = "0x" + STRING$(8 - LEN(t), &H30) + t
 CASE ELSE
  IF numBytes THEN
   b = ASC(LEFT$(bData, 1))
   IF b < &H10 THEN
    t = t + "0" + LCASE$(HEX$(b))
   ELSE
    t = t + LCASE$(HEX$(b))
   END IF
  END IF
  FOR ul = 2 TO numBytes
   b = ASC(MID$(bData, ul, 1))
   IF b < &H10 THEN
    t = t + " 0" + LCASE$(HEX$(b))
   ELSE
    t = t + " " + LCASE$(HEX$(b))
   END IF
  NEXT
  formatData = t
END SELECT
END FUNCTION

Note: This procedure lists most of the Constants and Registry functions available, but only uses a few of them in this demo. All of these functions, except RegCloseKey, have both ANSI (ending in A) and Unicode (ending in W) versions. I am not aware of any reason why both versions could not be used in the same program. To add the Unicode version, duplicate the function declaration, but change the ending A to W. Be sure that you know how to use the Unicode version!

WARNING! Use care when editing or altering Registry settings! YOU will be responsible for any damages incurred!

Your code contribution using the above Registry Libraries could end up here!

Windows Registry Access

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Windows Registry Access

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