OS on my laptop: Vista.
To keep it short, my laptop does not turn on normally anymore. When I turn it on, screen stays black, and lights keep turning on/off every minute or so, as if it was restarting.
I thought that taking out the battery and putting it back in, when laptop is turned off, would help. It actually helps, and laptop turns on as usually when I do that. However, it does not turn on anymore after I shut it down, or restart. Screen stays black.
My second PC at home actually had the same issue. It did not turn on, lights kept flashing. Turning power off and on worked again. I did full virus-scans with Kaspersky-Antivirus and Superantispyware. Scans did not really find anything, except 3 weird cookies, which were classified as a minor threat (1 out of 10), and 1 adware-not-a-virus. PC has been working as usually since then.
However, laptop is still having issues. It's got out-of-date NOD32 antivirus on it, which did not detect anything.
I'll be going to sleep now, and try to fix the laptop tomorrow. I plan to install avast and/or avira tomorrow.