Before making any recommendations, I have a few questions.
1. Does the new computer support USB 3.0 connections, and how many?
yes - 2 on the front panel
2. Does it have SATA 3 6Gb/s internal connection ports?
don't know about 3.6Gb/s, but yes, it has 2 free SATA internal connection ports. Odd behavior there.
It came with the hard drive in SATA0 and DVD/ROM in SATA2.
When I plug the old drive into SATA1, Linux sees it, but I can't boot Windows. EFI boot loads the grub bootloader from the old drive - which won't boot PCLOS, presumably because the disks are not in the order grub expects. Haven't tried to boot the XP partition on the old drive from GRUB - too scary. This is all pretty weird, no? The new drive is still SATA0 - why would EFI try to boot off of SATA1 just because it's there? If I try to 'legacy boot' off of SATA0, it doesn't see an OS at all. There's an EFI setup utility in the BIOS that seems to show the root directories of the first partition on each drive - I'm afraid to explore beyond that...
When I plug my old drive into SATA3, Windows boots and sees it as drive F:, but Linux (live CD) doesn't see it at all. The BIOS doesn't see it either. I don't see any options in the BIOS setup that would allow me to force it to see the drive as SATA3.
I can 'legacy boot' live CD's from SATA2 with the old hard drive in either SATA1 or SATA3.
3. Does it have eSATA external ports?
Don't think so.
4. What CPU?
i5-2330, I think (definitely i5, just not sure about the specific model - but it's the lowest-level one offered for the p7-1380t.
5. On board GPU or add in graphics card, and specifically what chipset?
On board Intel HD2500
6. PSU size, in Watts?
7. Amount of RAM... number of DIMM slots.
2 DIMM slots - both full. I think there are 6GB, but maybe only 4. Windows 7 is the 64-bit version.
8. Do you currently have any SATA to USB or eSATA external hard drive cases?
One other oddity - the integrated graphics has 2 DVI connectors and nothing else. The computer came with a DVI-to-VGA adapter, which I used to plug in my 23" 1920x1080 monitor (no DVI cable handy). This 'works', except that Windows and Linux can't identify the monitor. Windows still let me manually set the resolution to 1920x1080. Ubu12.10 does not. Mageia let me set it manually on the live CD, but won't apply it till I reboot - but I can restart X, and at that point xrandr lets me set the resolution, and it works. I assume PCLOS will behave like Mageia - my PCLOS live CD is scratched and I've yet to make a new one. Anyway, I think a DVI cable will solve that, but if you know the definitive answer... Also, when I power down the PC, the monitor doesn't sleep - it keeps displaying a 'no VGA cable found' message.
Thanks for your help,