Dynamic memory/ leaks

[hellowonn]

#include <stdio.h>
#include <malloc.h>
char* Hello();
int main()
{
printf("%s\n",Hello());
return 0;
}

char* Hello()
{
char* pHello = (char*)malloc(6);
pHello = "HELLO";
return pHello;
};

Will this cause a memory leak? Would the best way to be like :

#include <stdio.h>
#include <malloc.h>
char* Hello();
int main()
{
	char* sHelloString = Hello();
printf("%s\n",sHelloString);
free(sHelloString);
return 0;
}

char* Hello()
{
char* pHello = (char*)malloc(6);
pHello = "HELLO";
return pHello;
};

Is there ANY other way I can return a character string from a function without it losing its memory address, apart from using std::string? Sorry, just haven't quite grasped the concept..

And if I get a memory leak, what is the worst that could happen outside of my program? Because last time I did something before I learned about the free() call, I made a program that had LOTS of memory leaks and my computer started acting weird, stuff wouldn't copy,mouse would randomly click etc and I had to reboot. Just a coincidence? Or from memory leaks. Thanks.