I have an (ancient) HP Pavilion 7840 with a Cognac Motherboard (200731). Windows Xp was installed by someone after market and has never run properly. I found where HP shows the bios should be 3.07 and what was installed was 4.06 so I set the bios to hp specs. Using an old 3 gig HDD I can use the recovery discs to get windows ME on the machine, but when I try to put XP back on it gives me the error message: setup could not determine the size of 1 or more mass storage devices in your system. I have re-installed XP on this machine a couple of times over the years and have never had this error message until I changed the bios. I have an 80 gig Seagate Barracuda 7200.7 (ST380013A) hard drive and a 30 gig Western Digital (WD 307AA) hard drive. Whenever I connect either of these 2 drives as the slave it slows the computer down drastically. I am not sure what to do from here...Please advise

This may not solve the problem but instead of having two hard drives on one cable try putting one on the same cable of the cd/dvd drive, or have you done this?

Xlpho, Thanks for the quick response, but I don't know what you are suggesting. Should I try the 3 gig that works with ME or one of the others that don't work with anything?

Well if you can get both drives working I would install XP on the bigger drive and leave ME on the smaller one.

if you cable to the CD drive has a spare connection put the smaller one on that and put the bigger hard drive on another cable.

Could you tell us what you ultimately want ie, ME on 3gig drive XP on the other and dual boot etc...

Quick question did you have both drives set as slave?

What I want is 80 gig as master so I set it for cable select and 30 gig set for slave and have set if for this. They both show this in bios, but when I go to install in XP I have 2 options:
1 I let setup run without changing anything and then it comes up with an error message like 00000000007X so I have always pushed F7 and told it to install a standard PC with I/486. This is when I am now getting this error message about the hard drive not being detected. This unit has 2 CD burners and 2 hard drives so I was planning on using all 4 cables, but I will try anything to see if the installation will work.

Hmm...

Okay then, Have you tried removing the small hard drive and installing XP on the bigger one?

Also try setting both hard drives to auto select or master and anything else on the same cable as slave. Then set boot priority.

Does each hard drive work separately?

I am searching for correct jumper settings for the Western digital will be right back

Now I have a 3 gig hdd in as master with ME installed on it and the Seagate 80 gig as slave. When I try to run the XP install it still says same error: setup could not determine the size of 1 or more of your hard disks. Does anyone have any ideas?

yo may want to check your hard drives with Hard disk sentinel, in another computer, to see if they still good for booting.