Access Denied when initialize Disk - delphi

Question

I have following code:
if (APartitionStyle = 0) then //mbr
begin
hDevice := CreateFile(
PChar(ADisk),
GENERIC_WRITE and GENERIC_READ,
FILE_SHARE_WRITE and FILE_SHARE_READ,
nil,
OPEN_EXISTING,
0,
0);
error := SysErrorMessage(GetLastError);
if (hDevice = INVALID_HANDLE_VALUE) then
begin
error := SysErrorMessage(GetLastError);
result := error;
end;
dwIoControlCode := IOCTL_DISK_CREATE_DISK;
dsk.PartitionStyle := PARTITION_STYLE_MBR;
dsk.mbr.Signature := Random(9999);
lpInBuffer := #dsk;
nInBufferSize := sizeof(CREATE_DISK);
lpOutBuffer := nil;
nOutBufferSize := 0;
lpOverlapped := nil;
bresult := DeviceIOControl(
hDevice,
dwIoControlCode,
lpInBuffer,
nInBufferSize,
lpOutBuffer,
nOutBufferSize,
lpBytesReturned,
lpOverlapped);
if not bresult then
begin
error := SysErrorMessage(GetLastError);
result := error;
end;
I have executed the code as administrator or system and as user (with admin privilegs).
I have read something like: Driver is locked. Is there something missing in the code?
The handle is successfully created. On DeviceIOControl I get an error "Access Denied".

Answer 1

You are passing incorrect values to CreateFile(). You are using the and operator to combine bit flags:
hDevice := CreateFile(
PChar(ADisk),
GENERIC_WRITE and GENERIC_READ, { = 0 ! }
FILE_SHARE_WRITE and FILE_SHARE_READ, { = 0 ! }
nil,
OPEN_EXISTING,
0,
0);
You need to use the or operator instead:
hDevice := CreateFile(
PChar(ADisk),
GENERIC_WRITE or GENERIC_READ, { = $C0000000 ! }
FILE_SHARE_WRITE or FILE_SHARE_READ, { = $00000003 ! }
nil,
OPEN_EXISTING,
0,
0);