My canon MP730 printer went offline after I tried printing an address on a custom sized envelop. A repair Technician remotely got it back on the ready mode but I now get the message that the printer is not responding when I attempt to print. I have tried another usb cable and uninstalled and downloaded the drivers but problem persists.

This is rather "ancient" model as printers go, it come on the market in 2002. It is still available, this meant Canon done something ok with it...

You done everything what is available for home/small office user. I will try to help you solve this problem, but seem like motherboard on this printer is on the way out.

Please follow this procedure:

1. download and install ccleaner for all users, do not install yahoo or any other bar! I hate all bars with passion!
2. disconnect USB cable from your printer (or computer - whichever is easy)
3. uninstall all printer related programs and delete printer from printer folrder
4. switch off computer and wait 20sec
5. switch computer on and run it in safe mode (taping f8 during boot-up will allow you this selection) as an administrator
6. run ccleaner, as last run registry clean
7. restart computer in "normal" mode
8. install your freshly downloaded printer software and when ask, connect USB cable.

Simple removal of the printer and re-installation do not work as Windows have nasty habit of hiding old files adn re-use them even if you supply new ones.

If printer do not respond to this installation, to verify that this is a problem, try to install it on another computer. If it works on another computer, then you have something installed on this computer which prevent you from correct installation of the printer.

If that is the case - disconnect you rcomputer from network, disbale firewall and antivirus, then run ccleaner and clean everything what you do not need, go to tools and remove any program which you do not use or need, check your boot sector and disable all junk loading on the bootaup, be it any messanger, itunes, adobe or whatever installed itself there but it is not essential to run the computer. Run ccleaner again, then re-boot in safe mode and run ccleaner again, including registry.

Repeat steps 2 to 8 from above. but with disabled antivirus and firewall.

If your computer still will not see the printer, change usb port.

Hope this short advice will solve your problem, please let me know if it worked, canon unfortunately do not provide firmware flush options for home users.