I have an Asus G50VT-x5 laptop with nVidia GeForce9800M-GS graphics. Normally, Windows boots normally, but about 20% of the time (rough estimate), it will boot with the fallback VGA driver, maxing out at 800x600 with no Aero.
I've checked the system logs and there is nothing indicating an error loading the nVidia driver. It even specifies in the logs that the Nvidia Display Driver service started successfully, even though it has booted in safe graphics mode.
This has been happening for a while, but it's happening a little more often now than it was before. Since the first time my system exhibited this behavior, I have updated my graphics driver a handful of times.
I used System Information for Windows to check for problems there, but the only thing that stood out was the following:
Core Temperature 4486449 °C (8075639 °F)
Shaders Temperature 1171513530 °C (2108724330 °F)
I know this reading is incorrect, because my laptop is nowhere near the surface of the sun and my desk has not burst into flames. When it's opererating normally, I get a sane reading like [Core Temperature 58 °C (136 °F)] with no Shaders Temperature listed.
All I have to do to resolve the issue is reboot. I have seen no stability issues with the graphics or anything else. A long time ago, I had an issue with this computer where my framerate would suddenly drop during a 3D game from 40fps to <1fps, but after looking at the temperature readout immediately after quitting a game, I removed the bottom panel and blew the dust out of the vent and heatsink. Since then I have no drops in framerate under any situation.
I have uploaded a zip containing the SIW reports for when the problem is occurring and when the computer is operating normally. I don't have a paid account so it can only be downloaded 10 times, so please only download the reports if you think you can use them. If you try to download the reports and they are no longer available, please comment and I will re-upload them. If you want to look at the files, they are on Rapidshare.
EDIT
It happened again, and I looked a little deeper into the System logs. When this happens, there are a lot of errors about other device drivers unable to start. All of these errors are for PnP drivers. Also, my USB keyboard and mouse take a few moments before they actually start working, although this happens sometimes the first normal boot as well. I am quite sure this is related, so I am adding the pnp tag.
Also, CHKDSK will not run on boot. Even if a check is scheduled or a volume is manually set as dirty, CHKDSK will be skipped entirely, not even leaving an entry in the System logs. I tried running CHKNTFS /D, which did not work. I then manually changed my HKLM\System\CurrentControlSet\Control\Session Manager BootExecute value to the default listed on Microsoft's website. That did not work either. I ended up booting to repair mode and running CHKDSK there, which found a number of minor inconsistencies on my system drive, but none on my data drive. I have no idea if this is related.
Some more information for those who don't download my SIW report file:
Antivirus and Firewall are ESET Smart Security
I have three different virutalization programs installed: VMware Player, Windows Virtual PC, and VirtualBox. The network adapters for these show up in the log of failed device starts.
EDIT 2
I tried running sfc /scannow, which reported that it found corrupted files that could not be fixed. The CBS log is extremely cryptic. I tried booting to my install disk, launching repair mode, and doing an offline sfc from there, which produced the same result.
