error C2664: 'strcmp' : cannot convert parameter 1 from 'WCHAR [260]' to 'const char *'

HANDLE pSnapList;
        PROCESSENTRY32 p32Info;
    BOOL     p32Status;

    pSnapList = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );    
    p32Info.dwSize = sizeof( PROCESSENTRY32 );

                p32Status = Process32First( pSnapList, &p32Info );
                while( Process32Next( pSnapList, &p32Info ) )
                        [b][u]if( !strcmp( p32Info.szExeFile, processName.c_str() ) )[/u][/b] 
                                 processID = p32Info.th32ProcessID;



Microsoft unicode stuff.

You will likely opt to use either the "char" type of string, or the "wchar_t" type.
Visual Studio provides a std::wstring.

Note that wstring is a basic_string<> templated to wchar_t.

You may also opt to convert the "char" string to "wchar_t".
See MultiByteToWideChar: