# I had to shut down my pc three times. Why? **URL:** \ **Category:** Factual Questions\ **Created:** [December 22, 2005, 4:18pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807 "2005-12-22T16:18:06Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![D.E.S.K.Top668](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@D.E.S.K.Top668](https://boards.straightdope.com/u/D.E.S.K.Top668)\ **Post date:** [December 22, 2005, 4:18pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/1 "2005-12-22T16:18:06Z")
Ok, last night, I get done with my pc so I click on shutdown. The power light goes out and the fan shuts off. About half an hour later, I walk by it and notice that it’s on again. “No problem,” I think. “I must have hit restart by accident.” So I shut it down again and once again, the fan and power light switch off. I wait about ten minutes to make sure I didn’t hit restart again (It usually takes about two minutes maximum for the lights and fan to start up again.) An hour later, same thing; I walk by it and it’s on again. Fearing some kind of fault, I turn it off and unplug it. I’m running Windows XP Pro, ZoneAlarm, and AVG. I’m on comcast high-speed, but I don’t see how it can be an outside influence, seeing how it’s shut off when it happens. So, any advice on how to figure out what’s going on? So far, my only thoughts are either some sort of fault in the MoBo or power supply, or some sort of program hijacking me and faking a shut down when it’s really on a “delayed restart.” Thanks in advance - DESK ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 22, 2005, 4:20pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/2 "2005-12-22T16:20:45Z")
Your system may be set to ‘wake on LAN’ - there is a setting for this in the CMOS on most modern motherboards, although the default is usually off. Or it could be a dicky power switch, or a faulty PSU, or a bit of conductive muck somewhere on the motherboard. ---
**Author:** ![D.E.S.K.Top668](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@D.E.S.K.Top668](https://boards.straightdope.com/u/D.E.S.K.Top668)\ **Post date:** [December 22, 2005, 4:37pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/3 "2005-12-22T16:37:36Z")
I haven’t messd with the CMOS settings since I put the beast in a new case about six months ago. I’ve only had high-speed for about two weeks, but last night was the first time this has happened. Is it pretty safe to rule out some sort of outside influence though? As I said, I don’t see how that could be the problem, but I’m not computer savvy enough to know whether to rule it out. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 22, 2005, 4:45pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/4 "2005-12-22T16:45:43Z")
> [@D.E.S.K.Top668](#): > > I haven’t messd with the CMOS settings since I put the beast in a new case about six months ago. I’ve only had high-speed for about two weeks, but last night was the first time this has happened. Is it pretty safe to rule out some sort of outside influence though? As I said, I don’t see how that could be the problem, but I’m not computer savvy enough to know whether to rule it out. It may be that Wake-on-LAN has always been enabled but that it’s just never been triggered before. What sort of router/cable modem do you have? Is it USB-powered, or does it have its own power supply (if so, try switching it off when the computer is off and see if that stops the errant behaviour. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [December 22, 2005, 4:46pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/5 "2005-12-22T16:46:55Z")
> [@D.E.S.K.Top668](#): > > I’ve only had high-speed for about two weeks, but last night was the first time this has happened. Is it pretty safe to rule out some sort of outside influence though? As I said, I don’t see how that could be the problem, but I’m not computer savvy enough to know whether to rule it out. You would be surprised how many computer systems connected to the Internet are compromised and the owners don’t know about it. Many DoS (denial of service) attacks on big web sites such as Yahoo are caused by compromised computers with high speed connections, especially Comcast customers. See [http://news.zdnet.com/2100-9595\_22-5218720.html](http://news.zdnet.com/2100-9595_22-5218720.html) Your computer just might be a zombie. ---
**Author:** ![D.E.S.K.Top668](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@D.E.S.K.Top668](https://boards.straightdope.com/u/D.E.S.K.Top668)\ **Post date:** [December 22, 2005, 5:20pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/6 "2005-12-22T17:20:33Z")
> [@Mangetout](#): > > It may be that Wake-on-LAN has always been enabled but that it’s just never been triggered before. What sort of router/cable modem do you have? Is it USB-powered, or does it have its own power supply (if so, try switching it off when the computer is off and see if that stops the errant behaviour. I have a Motorola Surfboard (don’t know the model number, I’m using a friend’s pc right now.) modem, no router. It has it’s own P/S. I’ll see if anything happens unhooking the modem. > [@Duckster](#): > > You would be surprised how many computer systems connected to the Internet are compromised and the owners don’t know about it. Many DoS (denial of service) attacks on big web sites such as Yahoo are caused by compromised computers with high speed connections, especially Comcast customers. > > See [http://news.zdnet.com/2100-9595\_22-5218720.html](http://news.zdnet.com/2100-9595_22-5218720.html) > > Your computer just might be a zombie. Thanks for the heads-up. I have it buttoned up so tight that it occassionally even annoys me, but I’ll give it a check-up. Fortunately, I have an old Pentium II I can hook-up at home to check thing out before I put the Beast back on-line. Thanks - DESK ---
**Author:** ![PatriotX](https://avatars.discourse-cdn.com/v4/letter/p/c4cdca/32.png) [@PatriotX](https://boards.straightdope.com/u/PatriotX)\ **Post date:** [December 22, 2005, 5:28pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/7 "2005-12-22T17:28:36Z")
> [@D.E.S.K.Top668](#): > > I have a … modem, no router. That’s not good. Get a router ASAP. ---
**Author:** ![nivlac](https://avatars.discourse-cdn.com/v4/letter/n/3bc359/32.png) [@nivlac](https://boards.straightdope.com/u/nivlac)\ **Post date:** [December 22, 2005, 5:32pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/8 "2005-12-22T17:32:34Z")
\*\*D.E.S.K.Top668 \*\* , Why don’t you just shut off all power to the computer after it powers down? Plug it into a surge protector/power strip that can be shut off. You can leave the power on to your router/modem. ---
**Author:** ![D.E.S.K.Top668](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@D.E.S.K.Top668](https://boards.straightdope.com/u/D.E.S.K.Top668)\ **Post date:** [December 22, 2005, 5:36pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/9 "2005-12-22T17:36:52Z")
> [@PatriotX](#): > > That’s not good. Get a router ASAP. Why would that be? While I’m not adverse to an additional layer of protection, would a router help in any real way? I’m running ZoneAlarm (Pro) on the highest setting, AVG (pro), Windows XP Firewall, using Firefox, and have all my security settings on High. Would a router be any real benefit? Peace - DESK ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [December 22, 2005, 5:36pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/10 "2005-12-22T17:36:48Z")
OTTOMH, there’s 4 things that could make a PC start up w/o using the power switch \*Wake-on-LAN: already covered, check bios \*Wake-on-Ring: similar, but for your modem instead, check bios \*Various power-on-key settings: ie, turn on the PC if the spacebar is held down for 5 seconds; Check APCI settings in BIOS… do you own a cat? \*AC Power settings: You can set your PC to do 3 different things after a power outage: Turn on, stay off, or do whatever it was doing before the power went out. If you have it set to the first one, and you have a power-outage, your PC will turn on afterwards. ---
**Author:** ![D.E.S.K.Top668](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@D.E.S.K.Top668](https://boards.straightdope.com/u/D.E.S.K.Top668)\ **Post date:** [December 22, 2005, 5:48pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/11 "2005-12-22T17:48:29Z")
> [@nivlac](#): > > \*\*D.E.S.K.Top668 \*\* , > Why don’t you just shut off all power to the computer after it powers down? Plug it into a surge protector/power strip that can be shut off. You can leave the power on to your router/modem. While that would keep the problem from happening, it wouldn’t _solve_ the problem. I’m not too worried if it turns out to be a wonky P/S or BIOS setting, but if I’ve been hijacked in some way, I’d like to cut if off now. **Nanoda** , no cat, but I’ve got two kids. That’s why I got a locking case. Everything (On switch, reset switch, and all drives) are behind a locked panel. I’ll give you suggestions a try when I get back home. Thanks - DESK ---
**Author:** ![D.E.S.K.Top668](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@D.E.S.K.Top668](https://boards.straightdope.com/u/D.E.S.K.Top668)\ **Post date:** [December 22, 2005, 8:35pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/12 "2005-12-22T20:35:33Z")
Thanks for the help, all. Wake-on-ring was enabled…wheeew. If the mods don’t mind though, if anybody would mind taking up the router - why? question, I’d be most grateful. Peace - DESK ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [December 22, 2005, 8:40pm UTC](https://boards.straightdope.com/t/i-had-to-shut-down-my-pc-three-times-why/336807/13 "2005-12-22T20:40:08Z")
> [@D.E.S.K.Top668](#): > > Thanks for the help, all. Wake-on-ring was enabled…wheeew. If the mods don’t mind though, if anybody would mind taking up the router - why? question, I’d be most grateful. > > Peace - DESK A router for the hardware firewall, I’d imagine. That, along with a software firewall, is probably better than two software firewalls.