Advice at one time was to temporarily turn off av protection when installing software and some programs listed that step in their instructions. More recent advice has been to leave your av running - proper programs aren't supposed to trigger av alarms on install.
Is that still current advice? I had to reinstall winxp tab ed and now I have to install firefox, malwarebytes, word, open office, scanner software, etc. I upgraded to 6 prof from 5 when I reinstalled avast. It has the right-click option to temporarily turn off the shields. I'm using Word 2003, which is an old, finicky program and I wondered if current av protection might interfere w/ its install.