Computer waking up when telephone picked up?

Got a very strange question from one of my relatives today (I seem to get someone's broken computer every other day!!), and this one really stumped me.

If her computer is in "Sleep" mode and she picks up the phone her computer wakes up and she is shown the login prompt as though she had deliberately roused her computer.

Im not really sure if this is potentially a security issue or a hardware issue around her modem. Any ideas?

The computer connects to the net via a dial up modem

Computer waking up when telephone picked up?stinger

There is a power option choice called something like "Wakeup on Serial Port Activity. When you check that it causes that to occur. Go to Start, Control Panel, Power Options and uncheck that box to make the problem go away.

Computer waking up when telephone picked up?virus scanner

Hello,

You seem to have Modem's IRQ set as wake-up in APMS (advanced power management system).

Right Click on my computer-%26gt;Click properties. Then Goto Hardware--%26gt;Device Manager. In the next window choose select menu item View-%26gt;resources by type and expand the Interrupt Request section...

Now locate your modem name/model on the right pane and note down corresponding number.