Quadratic equation solver in C++
You have committed a grave error here with operator precedence, which should have easily been caught with simple testing:

X1 = Sector4Arithmetic / 2 * a;


The variable names SectornArithmetic are bizarre.  Most of those intermediate results don't need to be assigned to a variable.  The most complex intermediate result, b * b - 4 * a * c, has a standard name: "discriminant", which you should use.

You can use if (discriminant &lt; 0) to detect that there are no real roots.  The other tests — (b == 0) and (c == 0) — are superfluous and harmful, as there is no justification for prohibiting those coefficients from being 0.

As mentioned in the previous Python review, system("pause") is inappropriate.  Just call std::getline() and discard the result.

Calling main() recursively is worse than a goto, as you are deepening the call stack for no reason.  Write a proper loop instead.  Furthermore, the return 0; statement is unreachable and should be eliminated.