I’m running XP SP2. I have tried installing Avast, and said “No” to the initial scan on startup. When my machine restarts I log in, and the system will not start, it seems to be frozen, and the only way out is to physically press the reset button, and I have to go into Safe Mode to remove Avast, whereupon the system starts up normally.
Suggestions, please?
Did you have any other antivirus product installed previously (before installing avast)?
I wanted to use Avast in place of Norton A/V 2005 - removed. I was briefly using AVG, but that was also uninstalled before trying Avast.
NAV is notoriously difficult to get rid of check this link, which is a program removal tool, which can remove the remnants of a number of different Norton Programs:
Removing your Norton program using SymNRT. Download it, run it and reboot, uninstall avast, reboot and reinstall avast.
Welcome to the forums, normanallen. 
It is too often that people do not realize how hard it is to uninstall any Norton/Symantec product. They are infamous for this as their programs foul any other av from installing correctly by leaving behind files/registry entries that do not uninstall in the normal way.
Please follow David’s advice to completely get rid of Norton and then try avast in the manner Daivid suggested.
Well, that made quite a difference
Two remaining questions:
- There is apparently an incompatibility with ZA, and I’ve turned that option off. Any idea how long this has been going on, or how long it’s going to take to resolve?
- There are some features of Norton SystemWorks that are useful. Would any problems be caused by installing them?
- ZA free has no incompatibility, ZA Pro relates to its Privacy settings.
http://www.avast.com/eng/webshield_issues.html
- ZONE ALARM - AVAST Web Shield compatibility dialogue - Install/Update Question - YES or NO
If you are using ZoneAlarm Free you should click NO, because privacy features are not present in ZoneAlarm Free this will not turn off web shield transparent mode proxy.
Use a text editor and edit the avast4.ini file, the default installation location is C:\Program Files\Alwil Software\Avast4\DATA\avast4.ini (I would advise you copy avast4.ini before editing it, just in case).
Locate the line containing ZoneAlarmCompatibility= and delete that line. Save the edited avast4.ini file.
If you are using ZoneAlarm Pro and Privacy Control in ZoneAlarm is set to High and if you click YES in avast compatibility dialogue box the transparent mode proxy in web shield will be turned off you have to manually configure browser to access internet. To manually configure your browser watch instructional video
For IE - broadband users: - Tutorial - Web Shield Proxy Set-up for IE
For IE - dialup users - Tutorial - Web Shield Proxy Set-up for IE (Dial-up)
For Firefox users - Tutorial - Web Shield Proxy Set-up for Firefox
- I would be careful when you install systemworks (use custom install, etc.) that only the elements you want and shouldn’t conflict are installed (sorry I don’t know them I’ve never used systemworks) you wouldn’t want to go through this hassle again.
OK, that makes sense as I’m using ZA Free. Norton Utilities installed without any problems - that’s the only really useful bit, so I’ve found.
Finally (I hope), I was checking other users, and found that although the Avast processes seemed to be running when they started up, there was no blue icon in the system tray, and now when I logged back into my account its gone from there as well ??? I have been trying to work on that. Curiously, I can’t find it under ‘Taskbar and Start Menu Properties’, so I don’t know how to get it back.
If you were checking other users who didn’t have the avast icon, did you pick up on the questions they were asked and possible solutions they were given ?
Did you uninstall avast after running the Norton removal tool and rebooting as suggested above ?
Removing your Norton program using SymNRT. Download it, run it and reboot, uninstall avast, reboot and reinstall avast.
Other users on my PC!
I checked one of them myself. I have a program called WinPatrol running and it reported four new Windows Services: iAVS4 Control Service, Antivirus, Mail Scanner and Web Scanner. But no blue icon 
Avast was uninstalled first, then the Norton programs (as described above), then Avast was reinstalled, and worked. And I still don’t have the icon after logging back in.
WinPatrol blocked the ashdisp.exe startup entry.
Uninstall avast, boot, disable WinPatrol, install avast, boot, enable WinPatrol and allow the startup entry (icon).
Not other user on your PC, when you checked the posts of other avast users with the missing icon, they would normally have been asked about other security programs, such as WinPatrol blocking new start-up entries (obviously without telling you or your not knowing what ashDisp.exe was and denying it). The other entries that winpatrol did mention are services and don’t feature in the start-up folder, the only one that should is the ashDisp.exe.
Once you have done as Tech suggests you should get your icon back.
Wow. that hit the spot 
Now I complain to BillP about why it did that!
I would check the WinPatrol settings and see if there is anything about asking rather than automatically killing new start-up entries.
However, now you know about it, you should consider pausing, etc. WP when you are trying to install a new program. That way it should only react to programs that you haven’t elected to install.
BillP say it can only block something if its explicitly told to. I have a feeling my son logged in before I did and may have said No when he should have said Yes, and that may have caused the problem. Certainly I’ve never had the problem with WinPatrol before…it’s been very good about installing new things…
Anyway Avast is now being good, and had already reported on a couple of Adware files I didn’t know anything about ;D