David R,
Thank you for the reply, and for the excellent questions. I beg your pardon for my having not responded promptly after you replied to me so nicely, but I was offline for several days due to some issues that prevented my replying to your helpful post.
I will give the best answers to your questions that I can. [Note: I have spent three+ hours on this reply, tonight, making it as good as I can.]
FYI, I am on Avast! v8.1.3 Home Edition-Free now, and I can see only the simple GUI, and I have been unable tonight to evoke the dialog box that you included here. When I clicked on the Resident Protection: Standard item in the simple GUI, it showed me a small graphic at the bottom of its frame in its left, a graphic having the highlight bar in the middle position and word, “Standard.” I cannot find any other access to Standard Shield status in this GUI. So, I suppose that I MUST be on the Default settings in Standard Shield.
Is that supposition necessarily valid, based upon this observed evidence?
AVG 8.5 was installed, yes; and some unknown event a month ago caused it to stop working. I downloaded and installed Avast! Free for the trial that extends to Jan. 27, 2010. (I am considering the upgrade to Professional versus working out the AVG Uninstall problem and installing AVG 9.0)
At the initial event, AVG icon vanished from the Tray, and the AVG shortcut would not Start the app. Some of AVG’s processes were seen in Microsoft® WindowsXP® Task Manager still running, but no UI for AVG could be seen; stopping the remaining AVG processes took numerous tries and a reboot to make them go away. Add/Remove Programs reports, at every attempt, that the Change/Remove button (uninstall) on its AVG line fails!
After I ran the Uninstall that failed, and then I rebooted, I have not seen AVG as a running Application and not any AVG files listed by the Task Manager on its Processes tab. I tried to install AVG 9.0 back during this confusion, but it would not install, reporting that AVG 8 must be uninstalled first, before installing 9.0. And of course, as we have seen, AVG 8 will not uninstall, first.
Zone Alarm firewall also was killed by this event, and so I turned ON the Microsoft® Windows® firewall as quickly as I could, and then installed Comodo Free for trial as the fully capable firewall.
As for XP indexing, you may well be right. I will add that I am now seeing the Open File for Writing box asking me to approve …\Documents and Settings.…\MSS.exe much more frequently than I see the files in System Volume Information subfolders. The MSS.exe is shown by Avast to be invoked by “Program: searchindexer.e” (NOT searchindexer.exe) and “searchindexer.exe” is seen continually in Task Manager. It can be terminated by Task Manager, but in a few seconds, it reappears there, and I cannot get rid of it. Every time I reboot, the Indexing icon reappears in the Tray; and then I use its right-click menu to left-click upon the word, “Exit” and the icon vanishes from the Tray, but the program “searchindexer.exe” stays active in Task Manager>Processes. I found that I can stop the program in Task Manager>Processes. However, then the program re-opens in a few seconds, and this repeats every time I stop it with End process or End process tree in Task Manager.
I would stop that Indexer permanently, as you did, if you will, please, tell me how to make it happen!
By the way - if you could encourage Avast to include in next update a “fix” that would show the full path to the “Program:” and also the full path to the File that is being opened for editing, it would be a helpful improvement. The dialog box itself is not wide enough horizontally now, but this can be fixed easily by wrapping the lines and making the dialog box to stretch itself wider vertically, to fit the added lines. 
I still am troubled by whatever is behind the “Program: svchost.exe” that is repeatedly trying to “Open File for Writing” on these A[number].dll files. I thought it was the data for use in a System Restore operation, but I really do not know that. And if it is for System Restores, I should think that changing those files would invalidate the file as to the restoration of its specific date for restoration. Of course, I fear that this may be a signal, indicating that there is a persistent virus or bot or rootkit in my system.
Can you confirm for me, what is the System Volume Information used for? Why should these files be “written”? or even, why should the files be “read”? when there is no System Restore being performed at the time. ??
Your helpfulness is appreciated. I am very grateful to have your expert help!
Falling Rock
OS: Windows XP Professional SP3, 32b, regularly patched by Win Update / SYST: HP Pavilion a1040n / CPU: Intel P4 519J 3.065 GHz
RAM: 2GB DDR 4200 / HD: 155 GB free on system partition / AV: Avast! 4.8 Home Edition-Free, updated typically 2x per day
AS: Windows Defender updated every two to six days since Oct. '08. / Ad-Aware Free 8.1.3 / FIREWALL: Comodo 3.13.126709.581.
Firefox Extensions: NoScript 1.9.9.35; Java Quick Starter 1.0; IE Tab; Forecastfox; Flagfox; DownloadHelper; FireDownload; PDF Download; Move Media Player 7; LinkedIn Companion; Screengrab; WOT.
Firefox Plugins: *-IE Tab Plug-in for Mozilla/Firefox; *npmnqmp 989898989877; *Default Plug-in; *NPRuntime Script Plug-in Library for Java™ Deploy; *getplusplusadobe16241; *Adobe PDF Plug-In For Firefox and Netscape; *NPCIG 1.0.0.3; *Office 2003 Plugin for Netscape Navigator; *Shockwave Flash 10.0 r32; *Adobe Shockwave for Director Netscape plug-in, version 11.5; Windows Genuine Advantage 1.9.9.1; *Windows Presentation Foundation (WPF) plug-in for Mozilla browsers [Disabled]; *Npdsplay dll; *Next Generation Java Plug-in 1.6.0_17 for Mozilla browsers; *DRM Netscape Network Object; *DRM Store Netscape Plugin; npybrowserplus_2.4.21