Encryption/Decryption using bcrypt library

Question

I am calling the BCryptDecrypt function which is returning an error. I get the error 120 using getlasterror which means this function is not supported in this system (in msdn).

status = BCryptDecrypt( hKey, pbInput, cbInput, NULL, NULL, sizeof(DWORD), NULL, 0, &pcbResult, BCRYPT_BLOCK_PADDING);

pbInput is the pointer to address which contains the data to be decrypted, cbInput is the length of the file and pcbResult will get the size of the output file (decrypted data). BCryptEncrypt is working fine but BCryptDecryptis not working.

Can anyone please help me out? few lines of code related to decrypt:

status = BCryptOpenAlgorithmProvider(&hAlgorithm , BCRYPT_AES_ALGORITHM , NULL , 0); if (!NT_SUCCESS(status)) { return; }

DWORD cbKey = 0;
DWORD cbData =0;

status = BCryptSetProperty(hAlgorithm , BCRYPT_CHAINING_MODE , (PBYTE)BCRYPT_CHAIN_MODE_ECB , sizeof(BCRYPT_CHAIN_MODE_ECB) , 0);
if (!NT_SUCCESS(status))
{
    return;
}

status = BCryptGetProperty(hAlgorithm,
                    BCRYPT_OBJECT_LENGTH,
                    (LPBYTE)&cbData,
                    sizeof(DWORD),
                    &cbKey,
                    0);

LPBYTE pbKey = (BYTE*)HeapAlloc(GetProcessHeap() , 0 , cbData);
LPCSTR szpwd = (LPCSTR)Getpwd();

BCRYPT_KEY_HANDLE hKey = NULL;
status = BCryptGenerateSymmetricKey(hAlgorithm,
                                    &hKey,
                                    pbKey,
                                    cbData,
                                    (PUCHAR)szpwd,
                                    (ULONG)strlen(szpwd),
                                    0);

if (!NT_SUCCESS(status))
{
    if(hAlgorithm)
    {
        BCryptCloseAlgorithmProvider(hAlgorithm,0);
    }
    if(pbKey)
    {
        HeapFree(GetProcessHeap(), 0, pbKey);
    }
    return;
}

DWORD pcbResult = 0;
status = BCryptDecrypt( hKey,
                        pbInput,
                        cbInput,
                        NULL,
                        NULL,
                        sizeof(DWORD),
                        NULL,
                        0,
                        &pcbResult,
                        BCRYPT_BLOCK_PADDING);

DWORD cbError = GetLastError();
if(cbError != 0)
{
LPCSTR messageBuffer = NULL;

size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                             NULL, cbError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&messageBuffer, 0, NULL);