Converting Char * to unicode eqivalent

You only need tchar.h and the TCHAR type if you want to produce both ASCII and Unicode versions of your code. If you do it this way then you should use the following types:

TCHAR    character;           // a single character
TCHAR*   character_array;     // an array of characters, aka string
PTCHAR   character_array;     // same as TCHAR*
PTSTR    character_string;    // same as PTCHAR
PCTSTR   constant_string = _T("A constant string"); // all string literals should be coded thus.

The compiler will then generate the correct types and literals based on the setting of the UNICODE define in your project General settings.

If you are converting to Unicode only, then you can use the above types or redefine to all wide characters and use:

WCHAR    character;           // a single character
WCHAR*   character_array;     // an array of characters, aka string
PWCHAR   character_array;     // same as WCHAR*
PWSTR    character_string;    // same as PWCHAR
PCWSTR   constant_string = L"A constant string"; // all string literals should be coded thus.

If your program uses MFC or WTL then you could use CString as an alternative.