At a glance, these are interesting replies! The machine is 'only' 5-6 yrs. old and came shipped with XP 2002 Home Edition AND a 160GB SATA HDD.
The long and short of it is a friend of mine gave me this pc FREE! He found it and it was in pristine condition, minus the HDD and OS (of course!) So, he put an OEM spec HDD in it, put XP Home Edition on and registered it via the case code #. He mentioned that he went to the Compaq site and installed the correct SATA chipset driver. Personally, I couldn't find any SATA driver support at HP/Compaq.
I just bought a genuine, never registered Windows XP Pro SP2 Full Retail OS in the box that included the Windows hologram disk, SP3 disk, and the back up disk w/SP3, and the manual from a very reputable source. This person told me that I was going to need a floppy with the required SATA driver or the OS wouldn't install.
It's obvious I don't have a clue as to what's going on here. I can tell you this- I did go into Device Manager and looked for anything pertaining to SATA storage controllers and found nothing.
T_T, your reply makes sense- let me check the BIOS and reply back.
Of further note, when the OS got 'accidentally' wiped by an unscrupulous tech, they 'found' a copy of XP Pro and installed it using a volume license key. It installed fine, read the HDD and all that. Problem is I'm not sure about the source of that OS and have had nothing but trouble with it. That is the reason why I went on the hunt for an authentic XP Pro OS.
Thanks!