Can't operate my Lifebook E 780 any longer.

[Also One]

Hello,

Today I installed Avast free anti-virus and issued a boot-time scan. After the scan was finished the computer rebooted and somewhere along the boot process I got a message saying something about that the machine or Windows couldn't load or initialize something. I didn't take closer notice of the message since it also said that I could take a look in the event log, so I just clicked the OK button. And from there the computer has not been operational.

The mouse pointer is frozen. The screen is blank. Can't reboot using CTRL-ALT-DELETE and can't turn the computer off using the on/off button. The keyboard is probably frozen too.

Any help/advice is welcomed!

Windows 7 Pro 64-bit
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[Also One]

Problem solved! I had disconnected the main adapter; hoping that the computer would turn itself off when the battery run empty. It finally did so, and the on/off button then became operational.
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