Hello,
Since today (16/01/2011): I note that AVASTSVC.exe runs with a permanent use of 25% of CPU (instead of less than 1% the other days).
I didn’t install new softwares, and my surf is the same as usual.
I think a new version of avast is responseable of this new comportment
Heldon.
Config : Win XP (SP3) - Core I5/750 - RAM 4Gb - Avast Free 5.1.889
I have no problem on my XP Pro system.
Are you running XP Home or Pro ???
Are you running a scheduled scanning?
Any other security program that could interfere?
No problems here either, when you see this 25% activity, is the avast icon rotating (indicates scanning) ?
If not then usually there could be some conflict with another security application.
What other security software do you have installed, firewall, anti-spyware, etc. ?
Hello,
I am on XP Home SP3.
No scanning, no other sofware interfers (no more as usual).
It seems some users in the forum have the same pb since the 5.1.889…
I have to test further if it appends only with FireFox or with another browser …
Regards.
Well when browsing with firefox or any other browser, the web shield redirects http traffic through its local proxy so that it can be scanned. This process and all other avast shields are controlled by avastSvc.exe (the main scanning engine), so it isn’t unusual to see activity on avastSvc.exe whilst browsing.
Hello,
So, first : I think I’m going first to clean uninstall then re-install 5.1.889 in order to see if it is dur to a bad custominzing.
Regards.
Hello,
I made several actions, but my problem still remains.
0 - Stop network access
1 - Uninstall 5.1.889 with aswclear5.exe
2 - Reboot
3 - Install 5.1.864
4 - Reboot
5 - Open network access
6 - Open Firefox
7 - AvastSvc.exe run at 25% CPU usage
8 - Close Firefox
9 - Upgrade to 5.1.889
10- Reboot
11- Open Firefox
12- AvastSvc.exe run at 25% CPU usage
13- Close Firefox
14- uninstall Avast 5.1.889 again, reinstall 5.1.864 again
15- reboot.
16- I notice that AvastSvc.exe run at 25% CPU usage but without launching of Firefox or any browser.
→ The activity still remains between 24.6% and 25.3%, for several hours.
I don’t know what I can do to stop this activity ? 
Regards.
Please download: http://download.sysinternals.com/Files/ProcessExplorer.zip
run as administrator, find “AvastSvc.exe” process (avast! service) and when it’ll use 25% CPU, right-click and choose “Create dump → Full dump”. Then compress the dump file and upload it on our ftp, I’ll look at it, thanks.
please test only 5.1.889 version, thanks.
Hello,
As I have already Proces Explorer installed, I’ll make the dump file in the evening.
Regards.
you must use the latest version, older versions are not able to create dumps
I was about to start a new thread on this exact topic when I noticed this one was already running.
I too have version 5.1.889 installed on my computers and on most of them it is working fine.
However on one of my laptops after about five minutes Avastsvc.exe starts to use 98% of my cpu resources according to task manager.
The laptop is running XP Home SP3 (all my computers are running either XP Home or Pro SP3) and prior to this version of Avast I have had no problems with Avast on this or any of my computers.
I have tried disconnecting from the internet, disabling all the shields, and even uninstalling and re-installing Avast completely all with same result.
I am not running any browsers or programs apart from the screensaver on this computer.
I have now downloaded the version of ProcessExplorer.Zip which you suggested in the previous post and will try running it and creating a dump file later today.
Any help would be gratefully received as this has effectively disabled this laptop as the only way I can use it is by uninstalling Avast and not connecting to my network.
I wonder if it is a XP Home problem as I have no problem on my XP Pro system but I do not use Firefox though.
This is with Process Explorer v14.01
I see there is another thread running on the same subject started by Dragonfly_27z a couple of posts earlier where he was also getting 98% CPU usage which is the same problem I had.
Since I have downloaded and run ProcessExplorer.exe to try to create a memory dump of the problem it seems to have gone away on it’s own, which is also what happened to Dragonfly_27z.
If the problem re-occurs I will create the dump requested, but how do I upload the dump to the site ftp?
Using Windows Explorer, drag and drop.
Or using FileZilla, for instance.
I’ve got the same problem with 5.1.889 . 97% of CPU usage. When I try to make a dump with Process Explorer (14.01) I get a message : “Error writing dump file. Access is denied.” With other processes it’s OK.
WinXP Pro SP3.
Try disabling avast’s self-defense module. Go to settings - troubleshooting - untick enable avast self-defense module
Hope this will help you 
When I did this my computer hung up that I needed just reset it. When I run my comp it seems Ok now. Have no idea what that’s been. Hope that a malware (if it is) didn’t modify avast when I’d disabled self-defense module.
Hello,
I upgraded again in 5.1.889.
During the creation of the dump in Process Explorer 14.01, my system froze → so I have to wait the rebuilt of my RAID5 cluster.
I would do a test tomorrow evening.
Regards.
I’m running The new build on a Home XP machine with the process only consuming a fraction of 1%. So probably not a Home XP isolated issue.