Probably folder access rights… The reinstallation generally solves this…
Welcome to avast forums 8)
system
42
I had the same problem, and here is the solution that worked for me. If you uninstalled Avast in the past through the add/remove programs, you probably did not uninstall it correctly (as was the case for me).
Avast has a program to uninstall it correctly on their website. Here is the link that will remove the software completely from the computer. Then you can reinstall.
http://www.avast.com/eng/avast-uninstall-utility.html
For some reason, if you uninstall any other way, there are things left in the registry that will conflict with a reinstall. After removing it this way, reinstalling it works perfectly.
system
43
People, if all above fails, then RPC ERROR IS A R A M ERROR.
Try upgrade your bios, or adjust ram frequency to lowest/safest.
If this still fails, change your RAM.
Well… why are you saying that? I think RPC error won’t be related to hardware problems or RAM…
DavidR
45
Snap, this is I believe software and not hardware related, so I would appreciate where you found this theory/analysis.
system
46
I’m also now dealing with this problem. I used to have either Norton or Mcafee a long time ago (at least 2 years), but then switched to Avast. What do I need to do to rid my computer of any remnants of these programs?
I’m also running Windows Defender, Spycatcher, and Ad-Aware. Using Windows Firewall because of some kind of problem with Zone Alarm, but it was some time ago and forget what it was. IIRC, Zone Alarm had some kind of anti-virus capability as well. How much will any of this affect Avast? Thanks!!!
DavidR
47
system
48
hi i am also having the same problem. when i switch my computer the avast icon has a red circle on it and when i click on it says
‘The AAVM subsystem detected an RPC error’.
I am also trying get rid of avast from my computer when i try to remove the software it, it says
Avast!
a setiface error has occurred: 536870929
Try to reinstal or contact support, please.
i am really confused ??? what to do so could you please help…
Larc
49
-= Try Repairing avast installation via Add or Remove Programs → Avast antivirus → Change/Remove → Scroll down to see the repair function…
-= yawn its already 12:00… I guess its time for me to sleep… Good night to everyone…
DavidR
50
You could start by answering this question - Have (or did) you another AV installed in this system, if so what was it and how did you get rid of it ?
This is by far the most common reason for this problem.
Or if no other AV installed now or before, try 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. Ensure that you scroll down and select the avast direct download link for the English version and not Cnet as that is for an on-line installation (not what you want to do). - Direct download for avast Home, English version, http://files.avast.com/iavs4pro/setupeng.exe.
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.- 2. run the avast! Uninstall Utility, reboot. If step 1 failed, as it seems to have it may be necessary to run this from safe mode, once complete reboot into normal mode.- 3. install the latest version, reboot.
system
51
Solution to this is pretty simple by the way. Right click my computer and hit manage. Go to services and applications (the +) then press services. Under services locate ‘avast! Antivirus’, double click it and press start. Also set the drop down box to automatic. Voila! Fixed :). Press ok and close services box.
Edit: Avast still won’t be running on-screen protection so locate the avast icon in your task bar, right click it and hit “start on-screen protection”.
If the icon is not there open my computer, locate alwil software and avast4 (C:\program files\alwil software\avast4 by default) and run ‘ashDisp’. Then do the step above. 
system
52
hey i have the screen shot of this error i m getting
http://img809.imageshack.us/img809/4668/errorios.png
DavidR
53
Not good to tag along on a topic with three years since the latest post and the topic created almost nine years ago.
The avast versions will be completely different. So any suggestions offered here are unlikely to work. Outside of this error has been related to having another AV installed or remnants of you previous AV left behind.
So it would be best to create your own new topic, sans very large coloured text, not needed to get help.
In that topic answer the following question - Have (or did) you another Anti-Virus installed in this system, if so what was it and how did you get rid of it ?
skniazi786, which is your avast! version number and type?
Which was your previous antivirus before avast! and how did you uninstall it?
DavidR
55
From his image it looks like avast 7, but this shouldn’t continue in this nine year old topic.
system
56
And the problem still exist.
ver. 8.0.1489 avast! Free Antivirus
Previous AV’s:
avast! Internet Security - un-installed and cleaned with avast un-installing tool
After installing this free ver. I cannot register due to error and no engine updates are available.
avast! Antivirus service is not running and cannot start (starts and stops right away).
Only procces currently running is AvastUI.exe
Please help
diwax
57
I’ve also had this happen twice in the last few days after updates have occurred. To finally restart (remove the red X circle in the orange icon) I had to reinstall (as a restore didn’t work). Not sure why this happening. FYI I’m using the attached (paid) version of internet security-is the version you are using?
system
58
Hi,
So I found out what was wrong in my case.
What I did:
[ol]- Uninstalled Avast
- reboot
- used Avast Cleaner in safe mode
- reboot
- searched whole Registry to get rid of any Avast traces
- reboot
- installed Avast FREE[/ol]
it is working now as it should be!
Regards
system
59
I had uninstalled, booted, reinstalled and booted but the problem remains the same. I had also successfully unistalled AVIRA anti virus before installing AVAST. Please help
system
60
I am also having the same problem, Please somebody help