Путаница с типами данных TCHAR и char. Какой тип данных выбрать?

TCHAR frmdata1[] = L"-----------------------------7d82751e2bc0858\r\nContent-Disposition: form-data; name=\"file\"; filename=\"C:\\Windows\\temp\\hi.exe\"\r\nContent-Type: application/octet-stream\r\n\r\n";
     TCHAR frmdata2[] = L"\r\n-----------------------------7d82751e2bc0858--\r\n";
     TCHAR hdrs[] = L"Content-Type: multipart/form-data; boundary=---------------------------7d82751e2bc0858"; 
     DWORD len1 = wcslen(frmdata1);
     DWORD len2 = wcslen(frmdata1);
 
     char *str1 = (char *)malloc(len1);
     char *str2 = (char *)malloc(len2);
     ZeroMemory(str1, len1);
     ZeroMemory(str2, len2);
 
     WideCharToMultiByte(CP_ACP, 0, frmdata1, wcslen(frmdata1), str1, wcslen(frmdata1), 0, 0);
     WideCharToMultiByte(CP_ACP, 0, frmdata2, wcslen(frmdata2), str2, wcslen(frmdata2), 0, 0);
     printf("%s",str1);
     printf("%s",str2);
     system("PAUSE");
     exit(0);

DWORD len1 = wcslen(frmdata1)*sizeof(TCHAR);
DWORD len2 = wcslen(frmdata2)*sizeof(TCHAR);

#include <windows.h>
#include <sstream>
#include <shellapi.h>
#include <wininet.h>
 
#pragma comment(lib, "wininet")
 
int SendHttpFile(TCHAR *szFileName);
 
int _tmain(int argc, _TCHAR* argv[])
{
    
    SendHttpFile(L"C:\\Windows\\Temp\\hi.exe");
        
}
 
int SendHttpFile(TCHAR *szFileName)
{
 
    TCHAR szHost[] = L"127.0.0.1";
    TCHAR szURL[] = L"/upload/upload.php";
    TCHAR szUserAgent[] = L"Opera!";
    TCHAR szFrmdata_0[] = L"-----------------------------7d82751e2bc0858\r\nContent-Disposition: form-data; name=\"file\"; filename=\"%s\"\r\nContent-Type: application/octet-stream\r\n\r\n";
    TCHAR szFrmdata_2[] = L"\r\n-----------------------------7d82751e2bc0858--\r\n";
    TCHAR szHdrs[] = L"Content-Type: multipart/form-data; boundary=---------------------------7d82751e2bc0858"; 
    TCHAR *szFrmdata_1;
    char *szBodyBegin, *szBodyEnd; 
    char *szForm;
    BOOL IsSent;
    HANDLE hFile;
    DWORD dwFileSize = 0, dwContentLength, dwRwBytes, dwLastError, dwLenFrmdata_1, dwLenBodyBegin, dwLenBodyEnd, dwLenForm;
    BYTE *ReadBuffer;
    
    std::stringstream ssErr;
    
    hFile = CreateFile(szFileName,  GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (!hFile)
    {
        dwLastError = GetLastError();
        MessageBoxA(NULL, (LPCSTR)L"Error", (LPCSTR)"Error", MB_OK);
        return 0;
    }
    dwFileSize = GetFileSize(hFile,  &dwFileSize);
    ReadBuffer = (BYTE*) malloc(dwFileSize);
    if(!ReadFile(hFile, ReadBuffer, dwFileSize, &dwRwBytes, NULL)) return 0;
    CloseHandle(hFile);
        
    //SendFile
    dwLenFrmdata_1 = wcslen(szFrmdata_0)*sizeof(TCHAR) + wcslen(szFileName) *sizeof(TCHAR);
    szFrmdata_1 = (TCHAR *)malloc(dwLenFrmdata_1);
    wsprintf(szFrmdata_1, szFrmdata_0, szFileName);
    dwLenBodyBegin = wcslen(szFrmdata_1)*sizeof(TCHAR);
    dwLenBodyEnd = wcslen(szFrmdata_2)*sizeof(TCHAR);
    szBodyBegin = (char *)malloc(dwLenBodyBegin);
    szBodyEnd = (char *)malloc(dwLenBodyEnd);
    ZeroMemory(szBodyBegin, dwLenBodyBegin);
    ZeroMemory(szBodyEnd, dwLenBodyEnd);
    WideCharToMultiByte(CP_ACP, 0, szFrmdata_1, -1, szBodyBegin, dwLenBodyBegin, 0, 0);
    WideCharToMultiByte(CP_ACP, 0, szFrmdata_2, -1, szBodyEnd, dwLenBodyEnd, 0, 0);
    dwLenForm = strlen(szBodyBegin) + strlen(szBodyEnd)  + dwFileSize;
    szForm = (char *)malloc(dwLenForm);
    ZeroMemory(szForm, dwLenForm);
    memcpy(szForm + (strlen(szBodyBegin)), ReadBuffer, dwFileSize); 
    memcpy(szForm, szBodyBegin, strlen(szBodyBegin)); 
    memcpy(szForm + dwFileSize+(strlen(szBodyBegin)), szBodyEnd , strlen(szBodyEnd));
    
    HINTERNET hSession = InternetOpen(szUserAgent,INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
    if (!hSession)
    {
        /*
        dwLastError = GetLastError();
        ssErr << dwLastError;
        std::string strErr = ssErr.str();
        LPCSTR CstrErr = strErr.c_str();
        MessageBoxA(NULL, (LPCSTR)"InternetOpen Error", CstrErr, MB_OK);
        */
        return 0;
    }
   
    HINTERNET hConnect = InternetConnect(hSession, szHost, INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 1);
    if (!hConnect)
    {   
        /*
        dwLastError = GetLastError();
        ssErr << dwLastError;
        std::string strErr = ssErr.str();
        LPCSTR CstrErr = strErr.c_str();
        MessageBoxA(NULL, (LPCSTR)"InternetConnect Error", CstrErr, MB_OK);
        */
        return 0;
    }
    
    HINTERNET hRequest;
    hRequest = HttpOpenRequest(hConnect, L"POST", szURL, NULL, NULL, NULL , INTERNET_FLAG_RELOAD, 0);
    if (!hRequest)
    {   
        /*
        dwLastError = GetLastError();
        ssErr << dwLastError;
        std::string strErr = ssErr.str();
        LPCSTR CstrErr = strErr.c_str();
        MessageBoxA(NULL, (LPCSTR)"HttpOpenRequest Error", CstrErr, MB_OK);
        */
 
        return 0;
    }
 
    //dwLastError = GetLastError();
    IsSent = HttpSendRequest(hRequest, szHdrs, wcslen(szHdrs), szForm, dwLenForm);
    if (!IsSent)
    {           
        /*
        dwLastError = GetLastError();
        ssErr << dwLastError;
        std::string strErr = ssErr.str();
        LPCSTR CstrErr = strErr.c_str();
        MessageBoxA(NULL, (LPCSTR)"HttpSendRequest Error", CstrErr, MB_OK);
        */
        return 0;
    }
 
    InternetCloseHandle(hSession);
    InternetCloseHandle(hConnect);
    InternetCloseHandle(hRequest);
 
    return 1;
}