I worked this issue for over 10 hours yesterday and got nowhere. Maybe the braintrust here has some ideas.
I have an Asus essentio desktop, with Win 7 Ultimate SP1 installed. Yesterday AM I discovered that it was completely hung,so I turned it off and turned it on. First, I got a black screen, so I turned off and turned on again. This time it booted, but hung on the startup screen. Off, and on, and it went to the F8 screen. Start Windows normally, and it hung on the pasword screen. Off and on, F8 screen, safe mode selected, got past password and it hung. Same result when restarted in normal mode. Essentially, any attempted action would result in a hang.
With this Essentio, there was at first no F8 option for startup recovery. Eventually, I was able to do a memory test and it appeared to be OK. Memory sticks show up normally in BIOS. I did mess around with some BIOS settings and eventually returned BIOS to default settingsbut it did not improve the situation; if anything, it may have caused the computer to begin a restart loop -- Asus splash, F8 screen with 2 choices [startup recovery and start win normally], either choice failed and computer restarted.
Created a recovery disk on another computer. failed with message that it was imcompatible with Widows installation. Burned a Win 7 Ultimate SP1 install disk -- wouldn't even boot with it.
Meanwhile, BIOS kept changing. Boot options added options and eliminated options.
Eventually, I was able to get the onboard system recovery to run, and it completed. The computer ws then able to boot through the password, as much earlier in the day, but still hung when it got to the desktop.
I know this has been very non-specific, but it was a very long day, and I wasn't taking notes. What I am wondering is whether this sounds like a HDD failure, a motherboard fault, or a windows/software problem? I am bummed because this is the computer I use exclusively for audio recording, and it has a bunch of specialized software on it. Replacing it will be a MAJOR pain.