Ive recently hardwired my upstairs PC to my router. For some reason, the downstairs PC can see the upstairs PC but not vica-versa. It sometimes switches with the upstairs being able to see the downstairs PC.

They can always ping eachothers IP, but not resolve the host name.

Is there a way of forcing a refresh of the routing tables or something?

Im using a speedtouch 580 router.

have you tried
\\
to connect to the other machines?

if that works then its an issue with NetBios names,

were the wireless / wired networks on the router given different subnets?
(I.E one on 192.168.1.x and the other 192.168.2.x )

\\ didnt seem to work. last time, ill try it again next time it happens.

The IPs were on the same subnet.

Cheers for the reply.

Ive had the same problem before, doing all kinds of weird stuff (6pcs on the network here)

never been able to properly fix it tho

oly way I even fixed it was to format, never managed to trace what causes it either

Ive had this before as well, it was a firewall thing - disabling the firewall wasnt enough, it had to be uninstalled.

embarassingly in not using firewalls, except windows one, ill try dissabling it.

Its odd as it seems random, the only way ive found to fix it is to delete the unreachable computer from the routers list of computers, sometimes when it refinds the computer it can sometimes be accesed.

Grrrr

There are a million causes for this problem

Best thing to do is start simple and stick 2 PCs on static IPs and get them working. Then add a third, then a forth and so on. Once they are working with static IPs, drop them back to DHCP if you want