Random (my fav) loss of network shares.

[K A Hall]

I have 1 windows 8 pro PC that is basically being used as a file and backup server.
There are various other pc's on the nework running winxp, win7 home and pro and win8 pro just to fill you in.
All pc’s can see all the network shares that are intended to be seen, printers, shared directories etc.
I have 2 of the PC’s, one win7 Home premium one win8 configured to back up to the backup server using Fbackup at around 11pm at night when they are not being used.
I can run the backup jobs from each manually and they work fine but the scheduled back up doesn’t run. When I notice that the backup hasn’t run and I try to browse the network I can see the backup server is there but when I click to see what’s available I get “Windows cannot access \\COMPUTERNAME with error code Error 'code: 0x80070035.
I can get the pc to eventually show me the shared directories on the backup server a couple of ways. Keep trying by clicking the computer name in Network or I can reboot and all is well again.
For some reason the pc’s that are supposed to backup to the backup server are randomly loosing access to the shared directories on the backup server and like I mentioned the connection does come back but only if you mess around with it.
There are no special software suites on any of these pc’s other than malwarebytes pro which I don’t think has anything to do with this. Windows firewall is on for all pc’s as well but the connections are initially there so I doubt that’s it either.
There are all kinds of things I can think of to try such as set the servers network adapter to not allow the computer to turn off the adapter, set the servers hard disk to never turn off in power management and I have seen various things to try while researching but no one seems to have a solid solution.
Trying to get the network connections to be stable/always there by trying different things is a little maddening so I’m wondering if anyone has a good solution.

[EzyStvy]

There are all kinds of things I can think of to try such as set the servers network adapter to not allow the computer to turn off the adapter

Try that on the two pc's that won't backup.