Hi, David. Sorry to take so long getting back to you, but life beckoned.
Thank you for your detailed, informative reply. I especially appreciate your opinion, the facts you provide, and, I hope, the willingness to try to understand where someone else is coming from. If I may, I'd like to clarify some things and ask some followup questions in my response.
Well I don't know of what complexity you talk of with the web shield proxy, it is transparent in newer OSes with no input required of the user. Load is negligible in both RAM and CPU with modern systems with GB+ of RAM and fast CPU, but even with lower performance PCs it isn't a huge drain. If RAM is a factor then it is cheap and will improve overall system response.
Perhaps it wasn't clear, but both of my previous posts were about how I personally use Avast, and, in response to alanrf's request for justification, why I choose to use Avast this way. That's why I said I'm the only user of this PC, and, more importantly, that I practice safe hex. My PC is a nine year old 600MHz PIII machine with 1GB RAM on fully patched Windows XP SP3. As you can see, I've got plenty of RAM, which is confirmed by the Task Manager and a third-party page file monitor. My CPU is slow enough that page loading and rendering is severely CPU bound for non-trivial web pages. Hence my avoidance of any additional CPU load caused by the Web Shield. (No matter how small. I didn't measure it.)
I wasn't referring to complexity of Web Shield's setup, which does appear to be completely transparent to the user. I meant bugs and false positives, no matter how few, which are introduced by any additional layer of software. I usually reduce my exposure to these issues by limiting myself to software which provides functionality I need and features I find desirable. Since the Avast documentation indicates Web Shield blocks only the same malware that Standard Shield would intercept, I feel just as safe without it. It's possible I might feel differently if I actually downloaded malware occasionally, but the fact of the matter is I never have. None of the AVs I've used have ever found malware on my PC, except for eicar test files and false positives. Safe hex is my belt and Standard Shield is my suspenders if my belt ever breaks.
It is by far better to keep malware off your system, rather than have to actually try to remove it when it is on the system, IMHO, but that's just another opinion.
I don't have any experience with that, so I defer to your opinion. It sounds like Web Shield would help keep malware from ever getting saved to disk, but wouldn't a routine scan detect the download and remove it? There's no danger of actually getting infected, because Standard Shield will prevent any malware Avast has in its database from executing. Right? I'm not advocating that using Web Shield is a foolish waste, rather I'm trying to understand if it's essential for me.
Whilst firefox 3 has introduced scanning of downloads, it also stated it doesn't work with all AVs and guess what, it 'doesn't' work with avast as it clearly hasn't got a clue about what executable (ashquick.exe) to use and nor does it have anywhere to input the executable.
Aaack! The Firefox 3.0.6 Downloads window says something like "Scanning for viruses...", but you say that it isn't! I verified it doesn't load ashquick.exe with the Task Manager. I don't like Firefox misleading me like that, but the Standard Shield does scan the test virus file eicar.com as soon as an attempt is made to write it to disk, either by Firefox or my third-party download manager. Avast is the only AV installed on my PC. Is Firefox lying to me? Apparently IE7 doesn't automatically scan downloads either, but at least it doesn't seem to be claiming it does. No matter. I usually us a third-party download manager anyhow.
Edit: I've confirmed the erroneous and misleading "Scanning for viruses..." message in Firefox 3 in
Mozilla Bug 461989.
The Internet Mail provider when set to High, could be your first indication that you have an undetected or hidden spam bot on your system.
Why's that? Shouldn't Avast detect the spam bot's exe as malware and prevent it from running? OK, let's suppose this is a case where the bot isn't in Avast's database. I expect my personal firewall would detect an attempt to make an unauthorized Internet connection.
Anyhow, once you've allowed malware to actually execute on your system, isn't it pretty much "game over"? I'm probably being overly pessimistic here. I haven't had the experience with successfully repairing compromised systems you may have.
There are times when what you post on here is going to be read by someone with little knowledge and that could put them at risk, you only have to look at the rash of infected/hacked web sites to see just how valuable the web shield is.
According to my understanding of the Avast docs, the Standard Shield should prevent any malware from being executed that Web Shield would have caught being downloaded. Am I mistaken here? Have you run across any actual cases where Standard Shield allowed malware to run that Web Shield would have stopped? In any event, I'll leave the Avast configuration advice up to those of you that have more experience lending this assistance. I was just telling my story.
Just one more question. I haven't disabled the IM provider, even though I never use IM. (I barely know how to spell it.) I verified I don't use any of the programs in the IM settings dialog. But the Instant Messaging details page reports 205 scans in the last hour. The last scanned is
D:\Documents and Settings\Alan Baxter\Local Settings\Temporary Internet Files\Content.IE5\TLOT839l\indexCAPWRRU6.htm. What is it scanning if I'm not using IM? Feel free to spank me and send me back to the FAQ if I've overlooked this issue there.
Edit: Added Mozilla Firefox bug report.