Windows Experience hangs @ "tuning windows media decoding"

Just installed Windows 7 (64) on my new pc.

Installed all the drivers, and tried running the windows experience, but it hangs on 'tuning windows media decoding' and then after a while says it can't give me one.


Specs:
i7 860
8gb ddr3
ati 5870
gigabyte motherboard

Btw my cpu is @ 24C so it's not an overheating issue or anything.

Tried reading around but only saw people having this issue using VMworkstation. They were able to fix it by disabling 3d acceleration. No clue why I'd be having an issue with this though.

Any help greatly appreciated.
THanks!

Update: I did find some references to more than 4 gig of memory. I have uninstalled 4 gig of memory (2 slots) and I can now complete the tests without issues.
I have been unable to find out why this is so, however it aint the memory as I have tested both (admittedly not with programs designed to do so but doesnt matter what configuration I use, it wont fail if I only use 2 sticks of memory).
I'll check for a motherboard update maybe thats it.... or maybe its just ati giving me issues. I want 8 so I can confidently switch of my paging file.

Thanks for replying. I've confirmed that it isnt the memory over the past couple of weeks. I've increased my psu to 1000 too just in case, as I was on 620 (which should have been enough).

If it is the driver then it's a serious problem and I think we would have had more people replying to this thread. I actually think its a bad video card. The company I've bought the card off have requested that I send it back which I am doing today. I'll let you know how it goes. It could also be a seating problem with the video card, for my setup I have found it difficult to confirm that it sits correctly. I've pushed it in as far as it'll go (including destroying the case to get it out of the way) but it wont lock in, it concerns me. But as you can see I've done as much testing as I can (below), so I am going to pay my fav company some money to get them to confirm that its either a good or bad video card. If they confirm its a good card, I'll replace the motherboard and case (sigh).

On a side note I've also done the following:
- Tested all memory in various combinations with a memory checker (all clear);
- Reinstalled Windows 7 twice in both 64 bit and 32 bit flavours;
- Reproduced the problem with Windows Vista 32 bit (I dont have Vista 64);
- Downloaded the latest drivers for all components including but not limited to the motherboard and video card;
- Did the reinstall of windows 7 on different drives (one a ssd, the other a conventional drive);

I've been trying to fix it for a few weeks now, its rather frustrating. I've just sent the video card back by post and that'll take a few days so I'll write back then.