Hi Phill, I've the same messages with Win7 x64 on a DP55KG and bios v4507 (but reported as 3878...)
ASPM is a power savings chipset feature for PCIe bus. We disabled it by default on Kingsberg, but you can turn it back on in BIOS Setup if you want. Just know that some PCIe devices have known issues with ASPM. For example you might purchase some PCIe card and it works with ASPM off but suddenly starts to fail when you turn on ASPM.
If you want to try turning it on in BIOS, just boot to BIOS Setup, go to the power page and enable the question called "PCIe ASPM Support"
Thank you for your response. I should have mentioned I had found that setting and enabled it and still had the same message. The only thing attached to the PCIe is the graphics card (a Nvidia GeForce 9400GT). The message from Microsoft seems to imply the board has a known compatibility issue and it has been delibrately disabled by the OS. I'm not worried about the loss of power saving options for PCIe on a desktop machine, just a bit disappointing that there appears to be a compatibility problem.
The other errors are relating to ACPI issues.
While the board for me is working just great, it would be good to know what is causing these errors and that a fix might be on it's way to ensure full Windows 7 Compatibility and perhaps prevent problems showing up in the future.
Incidently a found these errors while trying to troubleshoot a "not going to sleep" problem on Windows 7, so while I think these reported issues have always been present, it doesn't help when troubleshooting to see these errors logged.
Phill, I don't know exactly your problem with 7 "not going to sleep" but I know some usb devices sometimes prevent sleep mode.
Often it's a keyboard or mouse.
You have to disable "This device can wake up computer" under power management tab in its property through the devices manager.
Thanks for the post.
Windows 7 was sleeping just fine, nothing had changed, except for an audio CD in the drive! I think it was this preventing Windows 7 sleeping as it kept awake just in case the audio wanted to played elsewhere (Media sharing, which I don't use).
All seems fine again with Windows 7 nicely going to sleep mode.