Dell XPS won't connect wirelessly to my Canon MX340? I have a wireless router for the internet that I am using right now

You can only connect your printer to your PC via wireless, not to the internet. Your MX340 is not WiFi capable and is not a computer. Linking it to your PC via wireless just saves you having to connect it by cable.

There is no need to use USB cable to connect MX340 to a wireless router.
If you don't want to use the printer as wireless, plug the printer cable directly into your PC USB port.

Have you opened Internet Options, Connections tab, Lan settings, Check Auto Detect. OR release and renew your IP address : http://www.wikihow.com/Refresh-Your-IP-Address-on-a-Windows-Computer Is your wireless adapter enabled? Drivers up-to-date? in working order? Have you run the diagnose in Manage Network Connections. What is your Anti Virus? Try connecting with it disabled?

Hello,
Is this your first router or you are replacing an existing one with this? If you had a router setup before don't name the wireless network the exact same as your old one unless you go into your wireless properties on all your wireless machines and delete saved profiles.
What kind of security are you using on the wifi? wep, wpa wpa2? If you are using wpa2 and have not updated all your computers to the latest service packs for windows you can have some issues as well. Some routers don't work well with ps3's, try setting the router security to wep and make a ten digit password.
Also the Dell XPS M1530's are known for bad performing wireless cards. You may be able to obtain an updated bios firmware from Dell's website to help fix this though i'm sure it's not the cause of why you can't connect to this router.
See if this helps, if not respond and I will give some more tips.
Chris

What version of windows are you running on the dell

Is the Printer switched on? Do you have enough rights to use the printer wirelessly? Have you printed documents over your wireless connection previously?

The network key is also known as the encryption key or passphrase. It is the password on your wireless network that you have to type in other the computer with a wireless device to connect to the Internet. You normally set it using by connecting to your wireless router using its IP address when it is connected to a computer. Use the Internet to find the default IP address for your wireless router. It is normally in the form 168.192.1.1 or something similar.

Yes it is very much compatible with your XPS M140 that transmits 802.11 b & g wireless connection. In which the Linksys WRT120N Router can accept a/b/g and N wireless connections.

I highly recommend this router if you want to use one.

Even if it's a new Dell, you may need to update either the drivers for the wireless card or the BIOS.

Also, verify which protocol your Dell is set to use (i.e. 802.11g, 802.11b, auto-select, etc.). Dell may have fixed to to a slower protocol for compatibility.

What operating system do you have running on the Dell? Is there a hardware/software firewall setup/installed?