If it wasn't due to an update or installed program it may have been a virus. It's hard to say without more information. If you don't have antivirus or anti-malware software I'd highly recommend you get software to do that. Malwarebytes is free and very good for anti-malware.
Without more information no one will be able to answer you question with any accuracy.
Do a virus and anti spy/malware check to make sure you system is clean and a virus is not force rebuting your PC. I recommend NOD 32 (free trial) or AVG (free).
If this doesnt find anything check that your PC auto updates don't have permission to auto reboot your PC.
Check you don't have an auto sleep setup when the PC is idle.
Other than this all I can think of with such little information is to re-install your operating system, make sure you have all your drivers before attempting this.
most likely a viris
it may restart several times
My computer does that some times it is usually getting rid of useless files
You might need to restart your computer and see if it pops up then. If it doesnt then you need a new computer.
You may need to restart your computer. At times, when you make changes, your computer needs to be restarted before the changes will take place.?æ
Some antiviruses can eliminate a virus, but often times you will have to do a complete memory wipe of your computer. If you do not know how to do so, contact a professional. There should be a CD/DVD or program in which you can restart the computer and reinstall the computer software.
As long as the UPS has power. UPS's have different run times.
cards are randomly chosen 7 out of 12
because you need to install it three times, then restart your computer, and it comes up! hope this helped! it worked for millions of people!
about 15
Usually, when there is power failure, the computer won't turn on. Other times, it may turn on but due to inadequate power, hard drives and optical drives may keep disappearing and reappearing in 'My Computer'.
To change a host name in Windows XP, click start, control panel, performance and maintenance, and then system. From the system screen, click the computer name tab, enter the new computer name in the dialog box, and click OK three times. Restart the computer for the change to become permanent.
Restart the level 3 times (by pressing the restart button) and the door will automatically open. See related link for screenshots.