Non music problem - Strange network thing.

Has anyone seen this.
 
My mail server and CCTV PC has developed a strange thing according to my router log it is trying to login to it more or less continuously.
 
Malwarebytes and Avast report no viruses or malware even with a boot time scan.  I can find no spurious programs running or background processes.
 
Any ideas good peeps?

No my router is locked down tighter than a ducks, better leave it there.  I have no port forwarding all in bound traffic is denied.  It has a built in firewall.
 
It is definitely something on the computer as I have physical disconnected it from the network as one would expect the log shows no more traffic.  Perhaps it is time to dump it as it is really old and still running XP.  Need to find a mother board with at least two old style PCI slots.
 
Thanks for the thought.

A comment on two PCI slots.  Its rare to find a current technology motherboard that has that.  Many of the new boards will have one PCI slot but the problem with most of these is that its not a true PCI bus slot but merely a bridge to the PCIe bus.  Many PCI cards will not work or work well with the bridged slots.
 
On my ASRock Z77 motherboard (and Z77 motherboards are mostly "old" now) there is one PCI slot and its a bridged type.  I have a PCI 5 port USB 2.0 expansion card that worked well on an old motherboard with true PCI slots, but it will not work with the bridged PCI slot on my motherboard.  I had to buy a PCIe USB port card to get the extra USB ports I needed.  Same way with my backup system that has an ASUS P8-Z77 motherboard, the PCI USB card won't work in the PCI slot in it either.