I would also recommend you DON'T close AVs during program installs, what is it that they are doing or trying to hide. If it is nothing untoward then there should be absolutely no reason to do this. The only exception to this would be if it were another security program and even then there would have to be a good reason given.
I have a Cannon Pixma iP4000 and I installed the software without disabling avast. However, as Alan mentions if you absolutely feel you have to I would suggest that the Standard Shield would be the only resident scanner effected, so you could pause or terminate that and re-enable after your done.