Desperately need help

Ok, this is my problem. My friends comp took a dump. A friend told her that it was definatelythe hard drive. I thought ok, lets find out how to replace it. But than was told by someone that it may be the a ram chip that's bad & to (think she has 4 chps?) And to rearrage them & or take them all out & try cking comp 1 by 1 to find the bad ram chip. Don't know if that makes sense to me but am willing to try that later today. Did try to reinstall Windows Xp & it just won't take it. That's the point where my friend told me that the Hard Drive was shot. NOt an expert in any way on computer, but want to help as $$ is tight. Can anyone here help me??

 

Any error messages? What happens when you try to start up the computer?

 

It's been a while, but think I had to continually go into the (safe mode) to get into the system.
Originally thought that the windows crashed, but when trying to reinstall it, it just wouldn't except it after trying like 3 times. Was told by a tech guy here that the hard drive was going but thats about it. His answer at this point was not to put any $ into it & that he would find a good used one & to just give the other comp a toss. But it's only about 3-4 yrs tops & cost a fortune. Originally the overheated & blew & he installed this super fan on there that's as loud as hell. And it was about 6 months later that the comp took a dump. Friend tried doing a diagnostic & said flat out that he believed the hard drive was shot. Than I was told it may be a ram chip by someone else, well the rest I already said. Money's tight & I'm def NO expert, but want to help so really appreciate anyone's help on this.