A quick note to say Avast installed and so far all ok BUT a few issues with Z Alarm on the way, leaving me without ZA for a while (unknowingly). No time to post now as it is grandaughter's birthday trip to see the Lion King today but hopefully more tonight.

It does look like that. Of course, prevention is better than cure, where possible, so an argument could be made that the software that updates its definitions more quickly and completely might have the edge. Only true if its detection ability is matched by its ability to block/remove, of course, as I know first hand only too well (and the reason I changed to Avast in the first place.) I have read a large number of forum posts saying things like "Help. My AV detected a trojan and says it quarantined it but its still there..." So I think removal is every bit as important as detection.And a quick reply. More of a referral. Depends what problems you have and what version of ZA you use, but that should give you a start on it. Most ZA problems with Avast have been to do with the firewall blocking Avast processes. Which pretty much shuts down the connection ability. But this seems a more recent type of problem.

Great show! Now, back to the 'Computer Jungle' :)
Thanks Tarq, again, some good stuff there.

What happened was:

ZA Free: installed Avast and in the process it warned me they were 'working on compatability issues' with ZA. I believe I selected something called a 'transparent mode' for ZA to permit progress.

Installation complete and I noticed the ZA tray icon was missing - 'transparent' thought I. After 2 mins browsing or so, my browser connection (both IE and FF) to the router stopped. Email and Ping access stayed. My laptop was 'broken out' of the cupboard and had no problems (still running an 'unaffected' AVG8). Only repeated reboots of the desktop restored the router connection.

I looked into the router log and it showed TCP FIN SCAN from an IP which resolved to 'Akamai' (About Akamai), a US company involved in internet business, the 'scan' log entry being coincident with router drop. I realised ZA was in fact not there at all, and reinstalled it, which required shutting down avast to close the true vector modules. With ZA reinstalled I have not had another router drop.

Some questions for the experts from someone well out of their depth:-

1) Why would the router drop the connection and what does the return of ZA the fold mean?
2) My router firewall is/was at 'high' - would this have protected me during the 'outage'?
3) I have seen (this AM) a couple of 'UDP flood' log entries (please bear in mind that I have not been a frequent reader of router logs in the past:)) - should I panic?
4) I have now checked my desktop via Shieldsup and it shows 100% stealth - can I relax?

Not an expert so will limit my response to telling you that I have been running ZA and avast! together quite happily for at least two years.

If you do a significant update (not the daily variety) of one then the other will ask if you are happy with a new version being there.

Thanks, fb - yes, they appear to be 'living in harmony' today. The post was in case anyone else encounters the same problem and to hopefully for someone to explain the mysteries of TCP and all that to me!

Would someone please tell me how to turn off the 'virus database has been updated'. I can't find an option. Thanks

Turning off all or some Avast sounds can be accomplished either through the Avast program settings in the menu (right click tray icon, program settings, sounds) or via the speaker icon in the system tray, or via sounds in the control panel.
BOAC, I'm not too versed in the way of firewall protocols; I don't know what a UDP flood log represents. (Doesn't sound all that great, though, does it?)
With a hardware firewall guarding the gates it would seem highly unlikely to me that anything nasty would have arrived down the web, unless you actually invited it, so I think you can probably relax.
An excellent "second opinion" antispyware scanner is MBAM (free and paid versions available.) This is the current "rock star" of the rogue scene, and it wouldn't hurt to scan with it, if only for added peace of mind.

Thanks Tarq - Malwarebytes has been on my desktop for 2 months now and is run regularly. Relaxing slightly!:)

I've installed Avast, left AVG on the machine but "switched on", and everything seems much the same, as you'd expect.

It looks as if Avast doesn't do a nightly scan of the whole computer, which AVG did, but if the incoming protection is working, that shouldn't be needed anyway.

You should uninstall one of them. They won't run happily together. If you run into problems, run full uninstalls on both, use the removal tools. (Disconnect from the internerd. And the Avast uninstall tool is here. (AVG's is at post 10.)
It's true Avast doesn't run scheduled scans, that's the downside of the free version. I consider that downside minor. They could have (like some other makers) reduced some other functionality. Like detection rate/cleaning ability. I'd run a manual scan once a month or so. The first time you do this, you'll be a bit bewildered. Any malware found, the scan will stop, waiting for you to tell it what to do. There's lots of advice about this at the Avast forum.

They aren't both running. I've turned AVG off while I decide if like Avast. I'll remove one of them in a while. So far, Avast annoys me by doing what looks like a BSOD when I start the machine - that'll have to go!

Yeah, 'fraid it's probably related to having two AV's installed, even if one of them is turned off.
If you can get past the BSOD and look in the taskmanager, you'll probably see processes from both apps running, even with one turned off.
An AV has to get it's drivers/services/magic bits installed at a core level to do its job, and they run at start, turned off or not.
Some antispywares do the same. AVG AS, AdAware2007, and A2, for example, all run services at start, whether the application is running or not.

No, I turned off the "boot" bit of AVG too.

The "BSOD" thing is like the Windows post-BSOD inquisition - same screen colour and fonts,but this is Avast checking stuff. It takes a LONG time to do its check before it lets the machine continue. It gets the "Esc" treatment from impatient me, whereupon the machine continues,

I suspect I ticked a "scan the machine for xxx at startup" box when installing Avast.

Anyway, it's managed to update itself once, and it's done the VRDB thing so progressing OK.

That's probably it. That will cause it to run a boot scan, which fits your description. (Looks a bit like the chkdisk scan.)
Hopefully it will just do that the once; once it's up and running you (should) have to command it to schedule a bootscan - a series of deliberate actions - before that will happen again. (The bootscan is a way of removing nasties that can't normally be deleted when Windoze is running. Handy tool, if you ever should need it.)
Re the VRDB, this takes several minutes and is visible by the animation of the second Avast icon. (The icons can be merged.) You can set it to generate VRDB when the computer is idle, which is how I've set mine. Takes a while to complete, but then only runs from time to time, I think following a Windows Update where the files concerned may have changed.

Like Keef, I too enabled the boot scan but have now disabled it as it is very slow - but thorough.

On balance I think AVG 7.5 was the best I have seen and I would PREFER now to return to AVG 8 - if only I could find this darnned 'another anti-virus/security programme' which is stopping re-install:mad:

Getting some assistance from the AVG forum at the moment, so will report further. In the meantime I have uninstalled Avast and am trying Avira free which seems to have better options.

Why don't you re-install AVG 7.5? I understand updates are still available until the end of the year. I'm still getting updates on AVG AS 7.5.

I did that earlier in the chain but it refused updates?

BOAC I subscribe to a web site that helps out with Windows etc. and they recently sent this out:

AVG antivirus is causing patching headaches

"As if we didn't have enough patching emergencies to deal with this week, a recent update of AVG's antivirus software knocked out some people's Internet connection. AVG's support page indicates that after upgrading to AVG version 8.0.196, your network link may fail.

If rebooting your PC doesn't fix the problem, follow the instructions on AVG's support page to download the fixfiles.zip file to your computer. Double-click the .zip file to open it, and then double-click fixfiles.exe in the resulting folder to run the utility.

If the glitch persists, the company recommends that you run a repair installation of your AVG app. If reinstalling your antivirus software doesn't get you back online, AVG advises that you contact the company's support desk for further instructions.

I became aware of the AVG update glitch when the program began to interfere with the collection and distribution of e-mail on my Small Business Server 2003 test system."

May be of help, maybe not?

What was the failure message? Sometimes you just have to keep trying at different times. Their servers seem a bit busy, sometimes.
Usually I can update AVG AS first time, but sometimes it just says update failed (or similar) and I have to try again.

OK, I'm slow.

How DO you turn off those "Virus database has been updated" messages? I wouldn't mind if they were small, but they take up enough screen space to be a pain.