Networking issues

[Zrock]

Hoping someone has some fresh ideas. I have my home network with my main computer running win 7 with my HP 1600 laser printer atached. I have 2 laptops bith with vista running. At one point i had them both networked to access the printer through the network. Yesterday i went to enable the backup on the 2 laptops to backup over the network to my spare drive. The one laptop had no issues, the second laptop will not connet anymore. I guess it has been that way for a few weeks. I spent all day searching the net yesterday and nothing. I checked the settings between the 2 laptops and they are identical. The laptop can see my computer on the network but will not connect. The running laptop can see the other laptop no problem over the network but my computer cannot see it? Im stumped im faiirly knowledgable in computers but this has me stumped. The only thing that has changed over the past few weeks is i added a Canon MG5220 printer to the mix and im using the wireless feature to print. Im pretty sure everything was still working after the new printer. I even disabled the firewall on both computers but that did not help.