update of avast virus definitions by manual downloading

updating avast pro antivirus 5.0.545 takes long time(infact terminates repeatedly in the middle) and never finishes. wishes to download avast
pro antivirus 5.0.545 virus updates manually. also require info how to install those virus updates on already installed avast pro antivirus 5.0.545.
any help would be highly appreciated.
thx

while updating received following error.
last encountered error:cannot connect to the dopwnload 363.avast.com

ENGINE AND DEFINITIONS updating previous version 1005006-1,updated
program updated previous version 5.0545, updated version 5.0.545
total time 29.05
ok

well i would uninstall, and install latest …we are at avast 7.0.1466 now.

use this to remove , read instructions. http://www.avast.com/uninstall-utility