Dimension 8300 support 3TB hard drive?

Are you sure you mean Dimension 8300, and not the XPS 8300?  Assuming that the Dimension 8300 is the one, I would mostly be worried as to whether or not the installed processor supported 64 bit operating systems.  The Dimension 8300 is just old enough that not all processors available at the time supported 64 bit.  Also, there is no easy way to find device drivers for the operating systems that would be required.  I'm thinking that you would be dependent on the drivers already contained on the OS disk.

Assuming that your processor is ok, you should be able to use a 3 TB data drive with Vista 64 bit or Windows 7 64 bit.  Those two operating systems understand the GUID partitioning table, and though you can't boot from the drive without the UEFI, you should be able to format the drive and store data on it.

If the XPS 8300 is what you're asking about, I am sure you could use a 3 TB drive.

You can find some additional data on 3 TB drives at the following links:

Hard Drives Greater than 2 TB Do Not Work on Existing OS's - Western Digital

Beyond 2 TB - Seagate

Using GPT Drives - Microsoft

Thank you for your reply, JackShack, but I believe I'm raising a different question.  I see people reporting that some older motherboards can only 'see' 3TB drives as 700GB, in which case as I understand it no OS or software can help.  I'm trying to determine if my Dimension 8300 (not XPS) has one of those motherboards, and frankly I don't expect we'll really know until we hear from someone who has tried it, perhaps me in a few weeks (since if it doesn't work, I do have a plan B to use the drive in a different computer).

Since you raise the software issue, I'll note that (assuming the motherboard can 'see' an entire 3TB hard drive), I'm familiar with several software utilities to allow it to store data (but not boot) from 32-bit Windows XP (which I still use):

Seagate Disc Wizard (available at http://seagate.custkb.com/seagate/crm/selfservice/search.jsp?DocId=218619&NewLang=en in one of the links you kindly offer) has the limitation of only making available the whole 3TB in "two partitions". 

Hitachi GPT Disc Manager at http://www.paragon-software.com/hitachi/ has my interest, as it boasts the ability to offer "one massive data drive".

Thank you very much, JackShack!

Hitachi GPT Disc Manager at http://www.paragon-software.com/hitachi/ has my interest, as it boasts the ability to offer "one massive data drive".

As always I ran the drive manufacturer's boot diagnostics** before ever booting into Windows, and I had a scare, because it only "saw" (and by how quickly it completed only tested) 801GB; but according to a email reply this morning from "...Hitachi Technical Support. We are in the process of updating the Drive Fitness Test. It is currently not compatible with our 3TB drives, and will not always run a proper test on it."

*model HDS723030ALA640 http://www.hitachigst.com/internal-drives/desktop/deskstar/deskstar-7k3000

**Hitachi Drive Fitness Test 4.16 http://www.hitachigst.com/support/downloads/#DFT

Drives Larger than 2TB usually require a controller with special bios and 64 bit OS.

Thats why the WD Drives came with a PCI-E non bootable controller.

Drives Larger than 2TB usually require a controller with special bios

Though I have had some issues.  While XP sees the whole drive, not everything does so well.  A Norton Ghost 14 boot CD can't, for example.  A software solution needs to be GPT-aware.

And I've discovered another twist Hitachi support said their testing didn't; even after installing the (aforementioned) "Hitachi GPT Disk Manager" on multiple XP computers, if I move the drive between computers, each computer for some reason only "sees" the files -it- wrote to the 3TB hard drive.

and 64 bit OS. Thats why the WD Drives came with a PCI-E non bootable controller.

What you are seeing is normal for a setup using a BIOS overlay.  When you use the Disk Wizard software you set up a special bit of code in the boot sectors that replaces some of the code normally used to control the hard drives.  Since this code only gets loaded when you boot from your normal operating system, anything that has its own boot code will not load this update and will have trouble talking to the drive.

I first saw this behavior with Windows 95, which depended a lot on DOS procedures.  My old 486 had a BIOS that couldn't see anything past 504 MB, so when I purchased my first 1.2 GB drive I had to use "Max Blast" to allow the OS to access the disk.  If I wanted to boot from a floppy there was a routine on the overlay that reminded me to hit a given key so that the overlay would be installed before the floppy booted up.  Evidently Seagate doesn't support booting from anything other than the installed operating system.

What you are seeing

is normal for a setup using a BIOS overlay.  When you use the Disk Wizard software you set up a special bit of code in the boot sectors that replaces some of the code normally used to control the hard drives.  Since this code only gets loaded when you boot from your normal operating system, anything that has its own boot code will not load this update and will have trouble talking to the drive. I first saw this behavior with Windows 95, which depended a lot on DOS procedures.  My old 486 had a BIOS that couldn't see anything past 504 MB, so when I purchased my first 1.2 GB drive I had to use "Max Blast" to allow the OS to access the disk.  If I wanted to boot from a floppy there was a routine on the overlay that reminded me to hit a given key so that the overlay would be installed before the floppy booted up.  Evidently Seagate doesn't support booting from anything other than the installed operating system.

As it is a data drive I would not think you would have any special problems moving it between computers.  Any computer you move it to, however, would need either the Disk Wizard overlay for its operating system, or be a 64 bit OS with appropriate hardware.  Otherwise the operating system would not be able to see all the sectors on the drive.  Remember what the basic problem is; the Master Boot Record style of keeping track of disk space can't count high enough.  That is why the modification to allow your OS to use the GPT is required.  Any computer you use to mount the drive will need to have an OS that understands the GPT.  It will need either the overlay, or a 64 bit OS that is GPT compatible.

In my bit of history above, the overlay had nothing to do with the booting of the floppy.  The installation of the overly simply allowed the BIOS routines to be replaced with routines that understood a different method of keeping track of the space.  In the Max Blast of about 1994, this overlay was put in the upper memory of the computer because that is where hard drive control was based.  Win XP and beyond have their own control algorithms in software and don't depend on the BIOS code, so the "overlay" is actually in the OS and you have no capability of booting anything other than the OS itself.

As it is a data drive I would not think you would have any special problems moving it between computers.

Any computer you move it to, however, would need either the Disk Wizard overlay for its operating system, or be a 64 bit OS with appropriate hardware.

p.s.  I keep writing "as I wrote" because some of these replies (and I'm not just talking about this last one by JackShack) aren't always making me feel people are reading what they're responding to.

EDIT:  I re-read the thread, and I think I'm beginning to see.  It appears that each time you installed the Hitachi software you set up a directory unique to the computer getting the installation.  I don't see how else you could move the drive amongst three separate machines and get different storage sets each time.  Are you certain that you have only a single partition?  I'm beginning to wonder if the software creates a new partition each time you set it up.

I'm confident that if I report JackShack's insights to Hitachi Support, I'll soon be able to report back on how this issue can be avoided.

Here's what happens with the Hitachi software:  Each time one installs it on a new machine, it first insists on only running if it can find a 3TB hdd, then it insists on 'formatting' the drive.  So now after doing this on two computers, my 3TB hdd has three partitions, sized 2794GB, 214MB, and157MB.  (There are 'advanced options' for formatting I haven't explored yet, perhaps I should, but I was hoping if I'd missed something [like doing that] Hitachi support [which has been very attentive and clear and responsive so far] would have told me about it already.)   The smaller files I write to the big partition from each machine also appear on the smaller partition created by each machine.  The huge files I've written to the big partition only appear on the big partition.

I've been careful not to alter their contents, because (while I don't really know what these little [by default "hidden"] partitions are for) I imagine one purpose is to store information which allows each machine to know how it is using the big partition.