First of all, don't plug your printer in.  
 
Go to canon's website, download the driver: for example 
 
Printer Driver Add-On Module Ver.1.10 (Windows 7/7 x64) 
aomwin110ea23us.exe 
1.10 
4.10 MB 
         
Just simply click on it, the program will run and unzip the drivers to window's directory (I don't know where, probably in windows/inf or system32). The PNP devices will search in these folders. 
 
Then plug the USB printer in, the window 7 will search for the installed drivers automatically for you. |