'Another computer on this network has this IP address'

[CornflowerB]

This message: 'Another computer on this network has this IP address' or similar wording popped up in a dialog box on my computer last night - I have seen this before also. Please could you anyone tell me what this means? I think my husband's computer and mine are on the same network, but why does this message pop up sporadically? Many thanks.

your router dishes out unique numbers to each pc/mac/console etc as it finds them, if you had a power failure or router failure or the pc was off but didnt clear its number (ip address) then came back on and the router had dished out that pc's number to something else you can get this

reboot the pc, if this is still happeneing, reboot the router or post back here and i will tell you how to either make sure it saves a unique number everytime or to make sure it receives one from the router everytime.

Thanks JBellingham, that's really helpful. I was paranoid that someone was accessing our network or something (can you tell I know nothing about computers?!) I'll come back to you if it keeps happening.
Much appreciated
Thanks again!

That happens in my house quite often as we have 4 teenagers and a lot of laptops.. a reboot usually sorts it:)