Printer Canon Pixma mx340 not detected. It worked fine before. I instaled everything again from original cd and nothing. I tried on diferent computers stil nothing.

Your drives for the printer have been compromised, this is a common problem when switching to new devices, some times even moving the same equipment to another room will cause it. First thing you need to do is get into the "device manager" and see if your ports are enabled. Click in 'Start' Icon then go to 'Control Panel" and 'R Click' on "system". This should bring up a box with several tabs at the top. [Before I go any further I don't know what system you are running so you can also access "device manager' by clicking 'Start" go up to "my computer" and 'R click" this will open a drop down box where you want to go to the bottom and 'L click" on "properties" it will bring up the same box]. As I said before this should bring up a box with several tabs click on "Hardware" when it changes the first icon down will be "Device Manager" "L click on it and all the important drives and devices in the computer open up before (you may have to click the upper right hand corner to get a full page view) Each listing will have a little box to the left of it with a [+] sign next to it. Go down the list until you come to see "Ports (Com & LTP ). This is the way it shows on most computers. L Click" and the [+] box and it will open up to your drives. "R click on the first one and a drop down list list will pop out giving you the choices, choose "update driver" and let the wizard do it's thing. This is more than likely your "COM" port for your internet connections. Go to the next one that may say printer port or may just have "LTP", do the same thing to it. This is probably the only two ports activated on your computer, if there are more perform the same thing on them. Now we've got the PC opened up to take the printer drivers, try running your printer CD again and carefully follow all the download instructions. This should put you back into the printing business. In the event that this doesn't work you may need to go to your search engine and type " Free download for (your printer name and model) pay special attention to any letters after your printer type, such as "mx340a or n etc. This can make all the difference in the world on your download. It may not have one but be sure you look it over good. When you restart your computer after activating the drives go to "control Panel" again and "R click on "printers and scanners" then "L click open" and it should show your printer. Again "R click on the printer and 'L click on open" and see if the computer wizard can find your printer. (This step should have been performed before you try the internet download. I got ahead of myself.) All of your files are in the computer or printer and this should activate the directory and register keys should pick them up. dhgill1949

I was struggling greatly too. The printer was connecting just fine to the WIFI. Went to check the network settings of the printer (I printed them) and saw that the IP address was in a different segment (192.168.0.x) and gateway was 192.168.0.1 when the rest of my devices were in the 192.168.1.x segment with gateway of 192.168.1.1 so went to manually set the network settings of the printer and placed it in the 192.168.1.x segment with the correct gateway. After that, re-ran the printer detection and voila!!! printer detected and working just fine. Hope that helps.