Posted this over in the Win 7 forum but realized this might be the more appropriate location for my query.
OK so I have been dealing with this issue for over a month. Here are the basics.
Small business network on Dedicated DSL from a small local ISP. Internet connection comes in from Modem then into Netgear WNDR4500 Router. WAN IP is 192.83.""."" subnet specified by the ISP, which I did not get to choose. LAN Subnet is 192.168.1."" . There is no domain or workgroup in place.
Netgear Router passes DHCP to all network clients and is the only DHCP source. There are only ever 15 devices MAXIMUM connected to this network, and only 4 of them are actual PCs( All Windows 7 Home Premium) with the rest being printers, iPads, cell phones, etc.
Hardline ethernet goes from Router Port 1 into a Netgear Gigabit Switch, which then feeds into the patch panel supplying internet to the 5 CAT5e network drops in the office.
All devices on the network operate perfectly fine without issue except for the Company owner's PC(figures) which is a desktop PC that never moves and is fed from the CAT5e network drop in his office.
His PC, multiple times per day warns him of an IP address conflict on the network, however he never loses internet connectivity and there is never an actual conflict. I have logged into the Router within 30 seconds of the IP Conflict message becoming present on his PC and there is no IP conflict to be found. DHCP is functioning and all devices show properly in the router list with their own individual IP addresses. Upon checking the Event logs on his PC, the TCP/IP errors are present and show an IP conflict, but instead of providing a MAC address or IP address that is conflicting, the logs show "" in place of what would normally be the MAC address and IP address in question. Like I said, there is no loss of internet connectivity at any point, he just gets the conflict pop up. I have given him an IP Config batch file to run from his desktop just as a pacifier although it really is doing nothing but releasing and reclaiming an IP and flushing his DNS cache. It solves nothing except keeping him temporarily quiet because he thinks it looks cool when the command prompt shows up and he feels tech(y).
DHCP range is 192.168.1.100 - 192.168.1.253. Default gateway is 192.168.1.1. Only 192.168.1.100 - 192.168.1.115 are ever claimed via DHCP due to the small amout of devices. I've tried setting him aside a reserved static IP outside as well as inside of the DHCP range, but not at the same time of course, They were set statically in his network adapter as well as reserved in the router by IP and MAC address. Again, internet connection good the whole time throughout all of these configuration changes but still, everyday he gets the conflict message. I have disabled all other network adapters within his PC as well to ensure it is not a secondary adapter causing this problem. Router firmware is up to date as well as all of the drivers on his PC.
I feel I have pretty much exhausted the options that I can think of off the top of my head at this point. Like I said, no other machine or device on the network has or has ever had this issue, it's just the one PC.
If anyone has any magic lined up, I'd love to give it a shot. The part that really has me stumped is that everything works perfectly fine except for this seemingly false flag warning. As is always the case, I cannot just ignore this as it signals to the owner that his network has issues, which I suppose it does, at least somewhere anyway.