anyone KNOW why a computer would turn on by itself?

My mom has a dial-up connection and Windows XP installed.  She's been having some power issues, it seems.  She would press the power button to power on her computer.....It will come on for a few seconds and then shutdown....sometimes the computer will stay on like it is suppose to, and sometimes it will not...........surrounding this issue, she also claims that her computer will automatically power on byitself.

I looked at it the computer briefly, attemting to narrow out the POSSIBILITY of a bad surge protector OR bad wall outlet.  I plugged the PC into ANOTHER outlet and the problem seems to be corrected...

However, I'm still curious as to why a her computer would automatically power on, given the circumstances... Theres a setting in either the BIOS or the properties that you can uncheck, it basically says that the computer will restart everytime a problem is detected.I found it, right click my computer and select properties, select the advanced tab and click  startup  and recovery.  It should be under system failure.  Good luck Quote

My mom has a dial-up connection

many motherboards will modem activity and power up the computer. This is a setting in the BIOS, I forget the name, but it should have a descriptive name. (the LAN equivalent is "wake on lan").

"wake on lan"