To enable file and print sharing (and ICS) you need to define a zone that encompasses all the IPs in your LAN (including any routers) and run the Trusted Network Wizard, selecting the newly created zone. After that, you should have open and secure communications across your LAN.
Curiously, if in the explorer I puts \pc_name, comodo asks to me whether I authorize port TCP 135, and if I notch to block, it does not block the accesses to the local network.