Does it still work with the original drivers from HP® Customer Support ?
Actually there are a bunch of fresh updates.
Do you have the "HP On-Screen Display Utility" listed there installed?
Maybe it's incompatible with newer drivers.
Sorry I wasn't more specific: the HP drivers no longer work (although they install just fine). Something got corrupted by the update I did from Intel's driver from some time last year and the latest version, and I can't seem to back-track.
NEW CLUE: I used prtScreen to capture what's going on in the "black screen mode". Windows lets me log in and run things (even though I can't see them in real time), so the screen capture lets me see some things. Note that even prtScreen's view of the world is goofed: most of the screen area is "blacked out" (I made dozens of these, all showing the same effect.
This message was posted on behalf of Intel Corporation
Since your computer is fully supported on Windows* 7 and 8, I recommend you to try a Windows recovery.
After that I recommend you is to install the latest customized driver released by HP*
We sell our Intel chipsets and processors to third party manufacturers and they design their own computers with their own features, settings and capabilities.
For that reason they design their own drivers, to meet the exact specifications on their computers. That is why I recommend you to try their drivers.
Please let me know the outcome.
Yes, I had already gone back to HP's original drivers both for the Intel and Nvidia chipsets.
Did all the simplistic repair paths, nothing did it.
Did an in-place "upgrade" (from Win7pro64 to Win7pro64) of windows, reinstalled all the service packs and updates. That was the only solution.
Everything works fine now, and I have 10 GB more free disk space (yes, there was that much cruft...)