I think I'm kinda late on the response but anyway;
From what I remember, you have to declare and initialise your variables. Also, you're missing some syntax stuff. I think this should work:
#include<iostream>
#include<stdio.h>
#include<conio.h>
#include<windows.h> //I added stdio, conio, and windows. not sure if they're necessary, but I used to use them.//
using namespace std;
int main(){
int count=0;
int inputNum=0;
cout<<"Please enter any number: "<<endl;
scanf("%d", &inputNum);
do{
cout<<"hello "<<endl;
count=count+1; //same as count++//
}
while(count<inputNum);
#include <iostream>
using namespace std;
int main (){
int count = 0;
int inputNum = 0;
cout << "Enter a number: ";
cin >> inputNum;
do {
cout << "Hello.\n";
count++;
} while (count < inputNum);
return 0;
}