My wireless is much faster that wired connection. Both the wired laptop and the wired desktop have the same firewall and antivirus software. Does this problem due to bad DSL router? What other factors could contribute to slower wired connection than the wired one?
Whoa there, back up a second. What type of connection are you referring to? Internet? Copying files between computers on your home network?
The fastest Ethernet for home LAN is GigE, or 1000Mbit/s (theoretical). This will beat any WiFi connection hands-down, since 802.11n only goes up to 300Mbit/s (again, theoretical). But Ethernet will be limited by the lowest common denominator, thus if you have a GigE LAN card but only a 100Mbit/s switch, your entire LAN will operate at 100Mbit/s maximum.
I found out that the problem was with the DSL modem. After a couple days after posting for the slower wired internet connection than the wireless, the old DSL modem ( 4 years old) stopped working all together and lost connectivity to the internet. Replaced by a new DSL modem, everything seems normal. Thank you all for the help.