Weird Boot Problem

[TurboTuna]

So, a little back information first.

I pinched an old HP Proilant ML115 G5 from work, and i used it as my main machine at home.

It has:

2x1GB of ECC memory

2x2GB of Non-ECC memory

I installed Vista x64 Ultimate with the 2gb of ECC. I then added the other 4GB.

Bosh. All working fine and dandy. I decide to do a re-install for some bizarre reason and this is where the problems begin.

My Vista Disc refuses to boot, it hangs at the faded grey loading bar. After much poking around i discovered that if i remove the 2x2GB it will boot fine..

I install, pop the 4GB ram back in and it refuses to boot.

Each and every stick by itself works.

The two 1GB sticks work together, but throwing any one of the 2GB sticks causes vista to refuse to boot, even if i just use both the 2GB sticks.

Bad memory i figure...Nope. I boot a Linux Live CD. Everythings correct and reported properly. The BOIS also reports everything properly, even if vista refuses to boot, however, XP DOES boot. and works fine.

Vista Memory diagnostics says everything is fine.

So, to recap my ramblings:

Memory: 2x1GB & 2x2GB

Any combination of a 2GB stick with a 1GB stick halts vista boot.

Both 2GB sticks work fine on their own

XP/Linux see all 6GB fine.

Does anyone have any ideas as to why vista refuses to boot? Baring in mind it was working fine before I decided to re-install & I've changed nothing in the bios.

I'm so tired, and i've probably missed something stupidly obvious so I'm open to ANY suggestions.

Thanks in advance!

EDIT: just to clarify: The RAM is NOT Bad, XP 64 see's it ALL and boots fine.

It hangs and doesn't boot just before the Vista progress bar pops up. safemode is also a NO-GO.

Edit 2: I've just realized, the only difference between OS's is That my 8500GT is installed in Vista. This was installed when i decided to re-install vista. So could it be the drivers? I tried booting in Low VGA mode but still a no-go.

Edit 3: Removed the graphics card, and the drivers. Still nothing. I'm stumped. All the sticks work on their own, but adding both 2GB sticks, or a 2GB ad a 1GB makes vista stop just before the loading progress bar.

Is it worth RMA'ing the RAM? Surely its not as it works fine in XP? :confused:

Edited November 29, 2008 by TurboTuna

[LiqHead]

Bad RAM.

[trashpickinman]

I think the problem is the mixing of ECC and non-ECC memory. I would try using all ECC memory.

[TurboTuna]

Thanks for both your suggestions, but the ram is not bad, and if mixing ECC and NON-ECC is the problem, then why did it work before?

[Guest xiphi]

Is an install with SP1 or without?

[TurboTuna]

Its with SP1

[TurboTuna]

Thought i'd give this a bump and see if theres anymore suggestions?