I got this motherboard about 10 days ago, as a stop gap updating my old s754 A64 3000+ to a C2D. It let me keep (some of) my DDR400 memory, and my 7800GS AGP. Quite a good board, for the money, though i miss my DFI lanparty.
Regarding the 8800 series incompatibilty, this isn't exactly Asrock's fault. 8800 GTS/GTX cards
require an x16 PCI-E slot. As the 775dual-VSTA only has x4 PCI-E it's just not going to happen. Perhaps with the 8600 cards though, if they have less steep requirements.
I'm not sure why the 8800's require PCI-E x16, maybe someone can get nvidia to explain it. I do know that some fairly recent SLi motherboards can't run 8800's in SLi, because they use dual 8x PCI-E slots when in SLi mode (versus a single x16 slot in single card config), and again that's not enough for the 8800s.
The chap whose system isn't booting into windows. Could i guess that after the bios POST screen, you just see a blinking _ cursor on a black screen? I had the same issue with my hard disk when i upgraded to this board also. I also considered my ram was bugging out at first, so just to rule that out, burn this image to disk (in Nero you go to the menu: Recorder - Burn Image...):
http://www.memtest.org/download/1.65/memtest86+-1.65.iso.zip
Pop the burnt cd in your cd drive and set the bios to boot from cdrom. If you want to save some time finding out if your ram is unstable, then once it loads, press c - 3 - 5 - Enter, to run the test that will show up the slightest of instability.
Once your ram is given a clean bill, then you'll know you've got the same disk error that i hit. For some very odd reason the 775dual-VSTA didn't like the partition table or MBR on my XP hard disk from my old computer. Even though my old computer still worked fine with it. It'd just sit there with that blinking cursor after bios POST, literally getting nowhere and not even reaching the boot menu.
The MBR on your disk is the master boot record, it tells the computer where to boot the disk from. The partition table is like the name suggests, a table that describes the number of partitions, and their size and layout on the disk.
The solution is to wipe the disk totally. Get some kind of fdisk utility or plug the disk drive into another computer that works, and delete all the partitions on the disk, so that the whole disk comes up as "unallocated" in whatever software you use (If you have another XP machine to do this on, i suggest Control Panel - Administrative Tools - Computer Management, then go to Storage - Disk Management).
Then you can try re-installing XP on the now-empty disk. This should be enough to get both the XP install CD's "detecting hardware configuration" screen and/or the actual XP boot process past that blinking cursor.
Erasing the MBR is a bit trickier, but that might not be neccessary. One solution is to create a new partition, and set that new partition to "Active" or "Boot", then reboot, then delete the new partition. Another method is to install some kind of third party bootloader/bootmenu on the disk.
In case you're interested, i think the actual problem is the 775dual-VSTA sees disk geometry ever so slightly different, for some drives. most likely it can't properly read the MBR to boot the active partition. so the fix is to remove the partitions/MBR that has this board all confused, and then set up XP on the board so that the MBR and partition table get written in a way that the board likes.
Oh... i also have a question...
My own board is a bit strange for overclocking. Anything over 295 fsb causes the boot process to stop dead after detecting RAM, prior to detecting the disks drives. However at 295 FSB it's rock solid stable. The ram is fine, i can even lower timings below spec at 295fsb. So is this a chipset issue? Any special bios setting to get it past this strange 'step' at 296fsb that suddenly stops it POSTing. I know the ram and cpu have a fair bit of headroom left at 295fsb. bios is 2.10, spread spectrum disabled, the various drive strength's are default, speedstep disabled, ram voltage high. Everything else is optimal defaults. Single PCI card installed, an audigy 4, and removing it makes no difference. Any help appreciated.