text: how does a computer restart itself after it is properly shut down? i have high speed internet through my cable . there are no telephones involved. i will shut down my computer, watch and listen for it to shut down and the light goes out on my tower and my monitor goes blank only to return a few hours later and find that it has restarted. what gives?  ron the biggest question how you shut your system down.  hitting the power button on your computer won't necessarily shut the system down.  it could put into standby or hibernation mode.  the only way to guarantee you're computer completely shut down is to go to start -> shut down & hit shut down.  alternatively, your system may include a "remote boot-up" option.  this is more common with business-related systems, which allows a person (like from the it department) to boot up a computer remotely.  you'll most likely will need to check your computer's bios to see if your computer has this option.  if your computer does have a "remote boot-up" option in your bios, you'll want to disable it as somebody may be trying to hack into your system & found out about this little option... making it even easier to hack into your system if you're not careful.  alternatively, you'll probably want a router with a built-in firewall to help prevent this (although it may not protect you from any roommates who are jerking you around with this).  finally, check for viruses & other malware.  there are some nasty stuff online which may have gotten onto your system somehow (either it's a brand new virus or you're too stupid/lazy to install & update an anti-virus program...  like my neighbor).  if it gets into the bios, it could be able to turn your computer on & off by itself...  although i'm unsure on exactly how, but it could happen as some computer components are becoming more software-controlled.  if this is the case, call somebody you know that's an expert in computers as you obviously need some help.  i hope this can help you out...  or at least give you some ideas to check.