Computer Wont Boot

hi i got a problem with my co0mputer its a compaq presario 5000 tower pc not laptop,can get windows xp cd to boot,then tryed boot cd with all sorts of stuff and still wont boot,its says missing operating system,maybe hard disk is nomore good i dont know,maybe a setting,ive been looking and trying all kinds of stuff and still nothing.let me know thanks,maybe its the bios or something need update i dont know so take care thanks

 

Welcome to MG.

Could be a duff Master Boot Record (MBR)

Boot with the XP installation CD.

When prompted, press R to repair a Windows XP installation.

If you have only one operating system, enter 1 to select it.

Enter the administrator password if prompted.

To fix the MBR, use the following command:

fixmbr