Finally! After some 2 months without a proper working PC I finally got my new machine, and what a machine it is... wow...
Intel Quad Core Q9300.
8 GB DDR2.
Radeon HD4850 X2 w/2 GB DDR.
1 TB + 400 GB HDDs. (ain't running out space any time soon...)
Remote control for Windows Media Center.
Windows Vista Home Premium 64 bit.
Windows Experience Index Score: 5.2
It's running oh so ever moothly, but sure wasn't a smooth start, no sirey!
It came with 'only' a Radeon HD4850, but I already had a HD4850 X2 at hand, so I wanted to swap the two.
But that turned out to be a 'complicated suggery'...
First of all... as with my other machine, the HD4850 X2 didn't fit onto the motherboard - the SATA connectors blocked it from being seated properly in the PCI-E slot.
The blue connectors on the left picture are the SATA connectors, the green slot is the PCIE, and the 4580 X2 covers somewhat well down over the (white) PCI slot....
On the right picture you can see how the 4580 X2 would be seated. That just doesn't cut it 
Here are the two GFXcards:
The 4580 X2 is about 25% longer that the 4580 that came with the machine. That in it self caused some problems. I had to remove a couple of brackets mounted beside the motherboard. Luckily they served no necessary purpose, so no harm in removeing'em.
The black cover had to go too... This proved to be in the way of the SATA connectors, so off with it!
Now it fitted properly! 
And off I went to install Vista. Sadly it's "only" Home Premium. I've been used to Ultimate so far, but the DVD had become too scratched to even be read. At least I got the option of choosing English as language! 
But.... after having battled with the setup and installing/uninstalling tons of software/drivers (it's incredible how much "garbadge" is being installed on these prebuild machines...) I dove into the Disk manager to partitionate the HDD.
Dunno what went wrong or what I did wrong, but the next time I rebooted......
"bootmgr.exe is missing
Press ctrl+alt+del to reboot"
Aw crap....
Luckily I had, for once, made the backup/recovery DVD's just before I started fiddleing with the partitions. I normally never make those.... 
Anyway... I had to reinstall Windows already after having had the machine less that 24 hours. New record!
But now it's been running happily for nearly 12 hours without a hitch!
The only nag I have come about is that no USB connection (memorycard/stick, external HDD) can be 'active' when booting. That prevents Vista, for whatever reasons from booting. Must be a 64 bit thing. Or what?
Here are some pics of the beast:
Outside:
Inside (with original GFXcard):
Outside, turned on:
