Have now twice accepted the message to update to the new version, on both occasions this has resulted in my computer failing to boot up.
Boots to a blank desktop.
Re-booted in safe mode, and uninstalled new version, problem goes away.
Gone back to running the 4.8-1229 version.
Running Windows XP Pro SP2.
Have (or did) you another AV installed in this system, if so what was it and how did you get rid of it ?
If not, you would be better doing a clean reinstall.
Download the latest version of avast http://www.avast.com/eng/download-avast-home.html and save it to your HDD, somewhere you can find it again. Use that when you reinstall.
Download the avast! Uninstall Utility, find it here and save it to your HDD.
- Now uninstall (using add remove programs, if you can’t do that start from the next step), reboot.
- run the avast! Uninstall Utility, reboot. If step 1 failed it may be necessary to run this from safe mode, once complete reboot into normal mode.
- install the latest version, reboot.
No other AV installed, have just done a complete fresh install XP on a fully formatted HDD.
Used Avast Uninstall to remove the update, then re-installed old version from my downloaded software storage folder.
Will try to do as you suggest.
OK, keep is informed of your progress.
Welcome to the forums.
What a Crock!!
Followed the instructions to the letter. even ran a registry cleaner after the uninstall.
Same problem again!
Have given up and gone back to 4.8-1229 version!!!
Hmmm… there were some improvements in last program update… Did you really try an installation from scratch like David posted?
Yes! Did a complete uninstall, ran a registry cleaner (Regcure), downloaded the latest version from the website using the link on David’s thread etc
This is also a fresh build of Windows XP, and no other AV has been installed on this build.
Have even tried diabling the firewall Online Armour so that there is no active anti virus, firewall or anti spyware program running in the background.
joevan, the exactly installation from the scratch is:
- Uninstall avast from Control Panel first.
- Boot.
- Download the latest version of Avast Uninstall and use it for complete uninstallation.
- Boot.
- Install again the latest avast! version.
- Boot.
- Check and post the results.
Also, can you uninstall Online Armor during the process and then install it again after all?
Thanks for the ideas, but have tried all of them without success, have decided to abandon the task and changed to another AV
Well… we tried and, after all, couldn’t even know what happened… for sure, a lot of users are with XP SP2 (yet) and running the latest version of avast smoothly.
Sadly, I liked Avast, but just do not have the time to struggle with upgrade problems.
When I am on leave after Christmas, will try the upgrade again, but in the meantime, I need a working PC.
Will let you know if I have any success
Regards
Joevan
We’ll be here to help you if you need 
Had some free time this weekend so started experimenting with the problem again.
The Avast update is incompatable with the firewall I was using, Tall EMU Online Armour.
Uninstalled this before installing the Avast update, and everything worked fine.
After re-installing the firewall ----- Boot failure again!
Tried installing Comodo instead, now every thing works!!!
Hope you guys can eventually solve this with some patches.
Regards
Joe
Thanks for the update and sticking with it.
Unfortunately there are a number of other topics where online armor is blocking the avast update without the courtesy to tell the user, so they are none the wiser and blaming avast for the failure.
Putting OA into learning or install mode (don’t know the correct terminology I don’t use it) also resolves the problem.
Unfortunately, the problem as it presents itself (not commonly associated with a firewall but another AV) doesn’t trigger our brain box to ask what firewall you use and once we were aware of it would have suggested the learning mode, etc.
There was recently an update to online armor that by all accounts might resolve the problem in OA.
My brain was also out of gear on this one, should have thought of the firewall option earlier myself.
Had similar problems with Zone Alarm a few years ago, when an upgrade started causing problems on the PC.
Interestingly, also tried to run PC Tools firewall, and this also caused instability on the system, as for thier Threatfire programme, find this is best left alone!
Yes, there are many that have issues with Threatfire, I have never used it myself though. There were enough hiccups to make me think twice.