How to remove scrollbars in console windows C++

You need to make the console screen buffer the same size as the console window. Get the window size with GetConsoleScreenBufferInfo, srWindow member. Set the buffer size with SetConsoleScreenBufferSize().

To remove the scrollbar, simply set the screen buffer height to be the same size as the height of the window:

#include <windows.h>
#include <iostream>
using namespace std;

int main()
{                
    // get handle to the console window
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);

    // retrieve screen buffer info
    CONSOLE_SCREEN_BUFFER_INFO scrBufferInfo;
    GetConsoleScreenBufferInfo(hOut, &scrBufferInfo);

    // current window size
    short winWidth = scrBufferInfo.srWindow.Right - scrBufferInfo.srWindow.Left + 1;
    short winHeight = scrBufferInfo.srWindow.Bottom - scrBufferInfo.srWindow.Top + 1;

    // current screen buffer size
    short scrBufferWidth = scrBufferInfo.dwSize.X;
    short scrBufferHeight = scrBufferInfo.dwSize.Y;        

    // to remove the scrollbar, make sure the window height matches the screen buffer height
    COORD newSize;
    newSize.X = scrBufferWidth;
    newSize.Y = winHeight;

    // set the new screen buffer dimensions
    int Status = SetConsoleScreenBufferSize(hOut, newSize);
    if (Status == 0)
    {
        cout << "SetConsoleScreenBufferSize() failed! Reason : " << GetLastError() << endl;
        exit(Status);
    }

    // print the current screen buffer dimensions
    GetConsoleScreenBufferInfo(hOut, &scrBufferInfo);
    cout << "Screen Buffer Size : " << scrBufferInfo.dwSize.X << " x " << scrBufferInfo.dwSize.Y << endl;

    return 0;
}

To remove scrollbars from the console, we can make the console screen buffer the same size as the console window. This can be done as follows:

#include <Windows.h>
#include <iostream>

int main() {
    CONSOLE_SCREEN_BUFFER_INFO screenBufferInfo; 

    // Get console handle and get screen buffer information from that handle.
    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    GetConsoleScreenBufferInfo(hConsole, &screenBufferInfo);

    // Get rid of the scrollbar by setting the screen buffer size the same as 
    // the console window size.
    COORD new_screen_buffer_size;

    // screenBufferInfo.srWindow allows us to obtain the width and height info 
    // of the visible console in character cells.
    // That visible portion is what we want to set the screen buffer to, so that 
    // no scroll bars are needed to view the entire buffer.
    new_screen_buffer_size.X = screenBufferInfo.srWindow.Right - 
    screenBufferInfo.srWindow.Left + 1; // Columns
    new_screen_buffer_size.Y = screenBufferInfo.srWindow.Bottom - 
    screenBufferInfo.srWindow.Top + 1; // Rows

    // Set new buffer size
    SetConsoleScreenBufferSize(hConsole, new_screen_buffer_size);

    std::cout << "There are no scrollbars in this console!" << std::endl;

    return 0;
}

Using #include <winuser.h>, you can simply do

ShowScrollBar(GetConsoleWindow(), SB_VERT, 0);

You can specify which scroll bar to hide using different parameters.