Missing Network Devices/Computers

Irritating problem: When I fire up my systems, about 30% of the time one or more of the computers or the Network drive will be missing from the list of devices on the LAN and be inaccessable except from some programs. I have to power down all three computers then power them back up to get everything to show up and be accessable.

Configuration: Linksys router, WD Worldbook 1T drive connected via Ethernet, Toshiba laptop connected via wireless, two desktop systems connected via Ethernet. One desktop running Win 7 MSDN distro, other two running RC 7100. Computers use WD network drive for backup and Outlook 2007 mail. Computers and WD have fixed IPs. It appears that the cause was too tight settings on the COMODO firewall running on the desktop and the laptop, and possibly a delay in the wireless connection being established with the router and other systems.

I had restricted "system" and "taskhost" from accessing the Internet. When I changed the settings to allow all input and output from any IP, and delayed looking at the network devices for a minute or so, the problem went away. (So far - fingers crossed it stays away.)

Bottom line - if you're running COMODO, let it make the access decisions initially, then check the Network Security Policy rules after a few days to see if any of the system programs need a more relaxed setting. If you have a wireless system in the mix, it may help to wait a bit, until the router lights stop flashing at least, before checking on the Network.