Vista - Seagate HD inoperable?

I'll try to sum this up as quickly as possible. What I need is advice.


Ok, so I have the HP pavilion desktop M9250f running Vista 64bit. The computer fails to load Vista. I am not able to use any F commands. None at all. It hangs at the HP Invent screen.

I already am aware of the Seagate Firmware, however in the early days of this problem was unable to find any of them that would work for me. The only way I found to get back into Vista was going through system recovery (F11) and then "cancelling". However now, it will not even do this.

I am not new to computers, and am in the stages of advanced troubleshooting.
I have tried every possible solution including:

Reformatting, extensive tests on all Hardware through multiple programs, Resetting the BIOS, Removing everything and replacing the CMOS battery, Hard Rebooting,
Vista Boot Disc, CHKDSK, bootrec commands, Called HP, etc etc.

At this point they were willing to take the compter back for repairs, but somehow it has turned into such a lengthy process (nearly 12 days later) that I do not even have confirmation a box is being sent. I exhausted every option and know that the problem is reading the Seagate Drives. My question is this however,

I am so tired of waiting on HP that I am willing to fix it myself at this point by taking it to a technician however that seems silly since I know exactly what my problem seems to be. What I need to know is if I just buy a new HD will the same thing keep happening? Is this in fact something HP "has" to take care of or is there anyway at all I can repair this computer myself?

I am unable to use any F commands so I am not even able to run the "Seagate Tools". I am 100% positive that the HD's are not fried, they are inoperable.
Would replacing the HD (not Seagate) solve my problem or is there more "flashing" that needs to be done?

Like I said, I have exhausted every possible solution. Without being able to access any F commands I am on my own in terms of tools. Can anyone out there relate or assist me with this problem?

Mega thanks in advance,

J