Question weird address bar Firefox issue in Win10 AND WinXP

[rickety_goodman]

On both my Win10 machine and my WinXP machines, internet networking works normally.
However,
on both machines (2 different versions of Firefox), if I type in a direct numeric address
(i.e., 192.168.0.167) which happens to be a network printer, which was addressable this way
until 2 days ago, I receive the message "Unable to connect". This happens on both the Win10
machine and the XP machine. It happens for ANY numeric network address entered on the
address bar of either the XP machine or the Win10 machine.
Obviously, I can't check the router settings because when I type in its numeric address, I
receive the error message "Unable to connect".
Both computers have been power cycled as have the router and the ADSL modem.
NMAP shows all the network addresses and the fact that they're active.
All the network peripherals respond normally during work sessions.
Except if the Firefox browser on either computer tries to access ANY peripheral by
its numeric network address, I receive the error "Unable to connect".
Doing a trace route (tracert) from a command line to ANY known numeric peripheral
address yields "Trace Complete" after only 1 hop.
What should I try next?

 

[ex_bubblehead]

Try these fixes i and see what happens. It sounds like your TCPIP stack just needs to be reset. No guarantee that any of this will work in XP.

 

[rickety_goodman]

I tried resetting the tcpip stack on the windows10 machine and it made NO difference.
Remember, everything is working normally when you are reading and printing information
from the internet or from that machine's local hard drive.
But you cannot find information from any of the 3 NAS units because asking either Win10
or WinXP to show the network connections that belong to its network only reveals its own
server and nothing else.
Each program should show another (different) computer, 3 NAS drives, 3 wireless printers,
a wi8reless camera, and its own network adapter.
Each program is only showing its own connection to the network through its own wireless
network adapter.
But I am posting this reply from the Win10 machine, so obviously everything except local network
discovery is working, including copying your answer to Notepad and sending it to the (invisible
now) wireless network printer to print it out.

 

[Alabalcho]

Can you ping that printer from these computers? "ping 192.168.0.167"?
If you do - try "http://192.168.0.167" as URL