If you have AVG and get a missing BIN file error on updating then,
Go to,
http://www.grisoft.com/ww.download-update
Download,
AVI: 270.6.4
IAVI: / 1616
Make a folder and add the two downloads.
Open AVG, click tools and Update from Directory then point it to the folder you made earlier.
AVG are working on a fix.