Hi I have used avast!4 for a long time.
I had some problems with ver 5 earlier, so I had gone back to ver 4.8.
Now there isn’t much of a choice, since support to 4.8 is ending.
In the last two days Update has repeatedly failed.
Can some one help please.
As before, I have comodo firewall and mbam. There wasn’t any conflict with ver 4.8.
Thank you.
Hello ravisunny2: Have you tried a repair of Avast. Go to Control Panel, Add and Remove Programs then choose Avast and Chang/Remove. Then scroll down on the options and Click ‘Repair’ Your computer will reboot.
I that does not resolve your issue then a Clean Uninstall and Reinstall of Avast is the next step.
As you have had v.4.8 previously and if you have not run the Cleanup tool (aswClear.exe) in SAFE MODE there may be remnants left that can cause issues with a newer version of Avast.
If the ‘Repair’ doesn’t resolve your issue then please follow these directions.
If you have had v.4.8 installed or v.5.0 or 5.1(beta) and had issues with the functioning of the version or an install of a newer version over top did not work properly, there is a possibility of File corruption. I have found this process to be extremely effective in many situations. Consider executing a ‘Clean Install’ using this format.
I recommend you follow these instruction in the order they are presented
Please download the latest official version of Avast (5.1.889) for the product you need and save it to your HDD:
[b]Free AV[/b]: http://files.avast.com/iavs5x/setup_av_free.exe
[b]Pro AV[/b]: http://files.avast.com/iavs5x/setup_av_pro.exe
[b] Internet Security[/b]: http://files.avast.com/iavs5x/setup_ais.exe
Then please download aswClear5.exe (Clean up Utility) http://www.avast.com/uninstall-utility and save it to your hard drive where you can access it easily.
EDIT> NOTE: It has also been suggested to run CCLeaner after you Reboot and before the Clean install of Avast. CCleaner is a powerful maintenance and cleaning application for the computer. The tasks that it is capable of performing make the PC work faster and in a more effective way
CCLeaner is Free and a Safe System Optimizing, Privacy and Hard Drive Cleaner> The latest FREE version can be found at: http://www.piriform.com/ccleaner/download. Choose either download links at the bottom of the box
If you have any problems please feel free to let us know. 
I agree with everything posted, especially needing the uninstall and clean install of Avast, but would add that when downloading CCleaner to use this web site below since they recently changed and added a paid business to the site posted above (the one below is FREE):
CCleaner, a system optimization, privacy and cleaning tool. There is a Slim version available as well at http://www.piriform.com/ccleaner/builds – 4th option down. It removes unused files (cache, temporary Internet files, etc.) from your system, allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. Additionally it contains a fully featured registry cleaner (you can make a back up in Documents if necessary).
Temporarily, the slim version of CCleaner is not available.
Today they released a new version v3.03.1366 (25 Jan 2011) and so far, all that is available is the installer with the Ask ToolBar and a Portable zipped version. Usually, within a day or so the slim version will be available.
Gopher John, Thanks for the updated information.
On contrary, I do not see Yahoo or Ask toolbar there… Seems it is only CCleaner now.
That’s true.
I have had loads of problems updating to 5.1889.
If you are still having problems I suggest you go to http://www.filehippo.com/download_avast_antivirus/ and download 5.0677.
They have a list of all previous versions and this is the last one that appears to download and work without any problems.
I would still use the Avast uninstaller to get rid of whatever version you are struggling with and then do a clean download of 5.0677, and pray that they keep supporting it, until they make the newer versions work properly.
It’s never listed Ask ToolBar on the download page. But that is the difference between the regular installer and the Slim version. There’s a little less than 1MB difference between the two install programs. Now Installers Hall of Shame http://www.calendarofupdates.com/updates/index.php?s=cb1803fb1c3a7b2d7da7f3a0c8bb5a49&app=calendar&module=calendar&cal_id=1&do=showevent&event_id=44514 is saying it now comes with the Yahoo toolbar.
It used to be mentioned in the CCleaner FAQ about Ask ToolBar, but I couldn’t find it this time, perhaps due to the fact that maybe Piriform is including Yahoo toolbar now.
Thanks Gopher John. I can’t believe from the time I posted until a few hours later Piriform changed the versions. Slim version will return in time as it always does. Thank you for finding that while I was off the forum. 
No problems, SafeSurf. I regularly visit http://www.calendarofupdates.com/updates/index.php?s=724d6b699581e8712bec853dc5ecd3d7&app=calendar. Their listing is regularly updated by members.
CCleaner v3.03.1366 Slim installer is now available for download at http://www.piriform.com/ccleaner/builds at the bottom of the page.
That was quick…thank goodness.
@ ravisunny2,
We haven’t heard back from you since your initial post despite us giving you suggestions. How can we help you further with your issues?