Sometimes I do want to chuck them all out and just keep my day job.

The hard discs/drives are all working fine now I'm glad to say.

Haven't run MemTest - I've never really had any reason to doubt the RAM. Do you think I have one?

Regarding the PSU, that's a good question. I had a guy do the installation of the MB and PSU and CPU into the case for me. Now he also put in the RAM, but put them into the wrong slots, so it's possible he's done something funky with the PSU too. But honestly, I got him to do all that because my knowledge in that area is very weak. I've built a bunch of computers now - but all of them have had the MB and PSU connected by someone else, because I don't know what I'm doing. How would I know if they are powering the CPU appropriately?

I have an Antec TPQ-1000 1000W TruePower Quattro ATX & EPS 12V Power Supply, Modular Cables, Four 12V Rails, 80Plus Certified, 2x8-pin PCI-E, 2x6-pin PCI-E

Ok - one more problem down... my drive was being weird because of AHCI being enabled in the BIOS. But I couldn't disable it - that would mean all the other problems would come back.

So I reinstalled my old Si3112 SATA controller and it now runs the BluRay/HD-DVD drive.

The Loading Windows screen time is very short now. Thank goodness.

In fact now, with the Highpoint, the Si card and the six SATA ports on the MB, that's 12 SATA devices in total I could have connected! Maybe that can be my next project...

John, glad to hear things are working out.

According to newegg, your Antec PSU has 1 4pin and 1 8pin 12v CPU plugs and a dual Xeon motherboard requires 2 8pin plugs. I had read that you should be able to use a standard Molex to 8pin adapter, but I recently was asked the question of proper voltage being supplied to the CPU using an adapter. I am not an electrical engineer so I don't know the answer. I would assume the adapter should be fine because Molex to PCIe power adapters work just fine and they supply close to the same power for the 8pin plug.

You really should run Memtest (Memtest86+ - Advanced Memory Diagnostic Tool) just to be sure. I had very odd and random problems due to a single bad stick.

One of these days I'll get around to running Memtest.

This power issue you're talking about (which goes right over my head) - how would I know if the board/CPUs are being powered correctly? What do the connectors you're talking about look like? I'm familiar with Molex plugs and the plugs to power GPUs, which I assume are they Molex to PCI-E adapters you mentioned. But I'm nervous that it could have been done wrong...

From 1st PC Corp.

Model Number: CB-4M-8F
"This 12" long cable adapter converts a molex 4-pin from a regular ATX power supply to either a P4 ATX 4-pin or a EPS 8-pin female by combining the dual P4 ATX 4-pin. This dual use cable adapter is black sleeved as well."
http://www.1stpccorp.com/Images/CB_u.../CB-4M-44F.png

Model Number: CB-4MP4-8F
"This black-sleeved power cable adapter converts a P4 ATX 4-pin female to a 8-pin EPS female connector. Cable length is 6 inches"
http://www.1stpccorp.com/Images/CB_u...CB-4MP4-8F.jpg

Model Number: CB-6M-44F
"This Dual-Use cable adapter converts a PCI-Express 6-pin to a EPS 8-pin, or a P4 ATX 4-pin, which is then plugged on to a motherboard. At 12-inch long and black sleeved, this cable adapter is very functional and looks sleek."
http://www.1stpccorp.com/Images/CB_u...-44F%20web.png

The power issue goes over my head also, so, I suggest calling a reputable system builder who deals with dual-CPU systems on a regular basis and see what they say.

The disks:

Ok, after hours of Googling and trying to solve the problem of the portable SATA drives not disappearing from Windows Explorer even after they had been disconnected and powered down, I found and downloaded a program called HotSwap from here which allows me to deactivate the drive before unplugging it. This was imperative as I had a drive get corrupted by removing it, thinking that no data was going to/from it. Luckily it was a backup, because there was 270GB worth of footage on it!

Now I can be sure.

The power:

As far as I can tell (and I'm not too switched on when it comes to this stuff, all of the power connectors come straight from within the power supply and go straight to the motherboard with no adapters.

Also, looking at the motherboard manual, it looks like all that is required is one 8 pin (plus the other stuff). Am I right?

You are totally fine and I think this confirms the use of Molex adapters. I looked at pictures on newegg to confirm, and there is the 8 pin above the top cpu and there is the 4 pin + Molex you pointed out. Because Supermicro builds a server class board like this, then its certainly ok for boards without the molex connector.