I have a desktop computer that is connected with wireless router by LAN cable and I have laptop that connects to network wirelessly. I have shared some folders on both computer but I cannot access files on my laptop when connect to shared folders from desktop. I can not even see laptop computer although I put them both in the same workgroup. I fear this have some connection with mixing network connections and wireless router. What do you think?
No, it cannot have any connection with wireless router. You should treat wireless network the same way you treat wired network because they work in exactly same way. Your problem is, I think, firewall on laptop computer. Try pinging laptop ip address from desktop computer. If you get no response then you will have to configure firewall on laptop to enable access from desktop computer.