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When I turn on a PC, another PC at the next desk turns on too?  What's up with that?

Gary Fuqua, CISSP
I have a strange problem.  I have two PCs connected by an Asus RT-N12 router/firewall.

PC1 is an small form factor HP Compaq DC7900 ultraslim desktop
PC2 is a full size desktop tower  HP Compaq 6200 Pro Microtower

Starting with both computers completely powered off.
If we turn on PC1, a few moments later PC2 will turn on by itself.    Very strange.

Lan Boot on PC2 is disabled in BIOS.
Nothing unusual seems to be installed on PC1 in startup (e.g. Wake-on-Lan utility)

Any ideas as to how this could be happening?
We unplugged PC2 to confirm that it is actually powered down.
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Technical Lead Manager (Owner)

you don't have to check Lab Boot, maybe there is a tool installed on the PC1 that send Wake on Lan request to PC2.

Check PC1 installed software and see if there is ant SNMP tool installed and configured to make a Wake on Lan.


noxchoIT Product Manager
Top Expert 2009
Simply disconnect the network cable from a PC which boots automatically. Then turn on PC1 and see if the second one boots as well.
Distinguished Expert 2019
i have seen this kind of thing happening with faulty PS, or AC cabling
so you could try another PS -  or swap it

another test would be swapping the pc's  - and check if the problem follows the PC - or the location
Danny ChildIT Manager
Another possible cause could be the power settings in the BIOS.  Some systems can be set to power UP after a power cut, and if these PCs are connected on the same power strip/surge protector/UPS, and this is a bit iffy, the 2nd PC could be perceiving the startup of the first as a power dip/cut.  Long shot...


I still can't figure it out after exploring all these options.   Not going to waste any more time on it.    My guess is it has to be bios related, but I don't see anything configured to cause the action observed.
Distinguished Expert 2019

did you actually change the PS -as suggested ?  easy and fast test


No.  It's a small form factor computer so we would have to order a special part to try this option.      It's more of a curiosity than a problem.