Hi fantom,
Welcome to Vista Forums!
Are you certain that the hard drive in the machine is the same one that came with the computer when originally manufactured? In effect, what is the manufacturer, make, and precise model of the hard drive? And while you're checking, unplug and replug all the hard drive connectors to make sure that isn't the problem.
As you did not purchase the machine from the manufacturer or new, are you absolutely certain that it ever had Vista installed on it? Could it have had XP and the prior owner tried to upgrade from XP to W7? I'm trying to verify that the machine (or at least the hard drive) is in fact compatible with Vista.
Also, what version of Vista do you have (32-bit or 64-bit)? How are you installing Vista (with a genuine Vista Installation Disk, with a Recovery Disk from the Manufacturer, or how)? How exactly are you installing the drivers and when you say it doesn't work, how do you know this? Are you getting an error message? If so, what does it say EXACTLY word-for-word and when does it occur?
Thanks! This information will help us try to find the cause of the problem. Please answer ALL the questions as there's no telling which one might be the key to identifying the cause and resolving the problem.
Good luck!
