Problem solved. Thanks very much for your help!

After checking the aycdd.ini file and determining it wasn't a normal test file, I took all the aycdd files to the Recycle Bin. I can always restore them later. Here's the HJT log:

Logfile of...

I sanned all files at Jotti's. All scans came back OK. No log files were generated locally, and I didn't think there'd be any point in copying and pasting the results pages from the web site. I...

Logfile of The Avenger version 1, by Swandog46
Running from registry key:
\Registry\Machine\System\CurrentControlSet\Services\binuqfvw

*******************

Script file located at:...

I could not delete ddcya.dll, either in Normal Mode or in Safe Mode; the file was in use both times.

I'm still having the problem.

Here's the HJT log:

Logfile of Trend Micro HijackThis...

Avenger log:

Logfile of The Avenger version 1, by Swandog46
Running from registry key:
\Registry\Machine\System\CurrentControlSet\Services\okwjdwsu

*******************

Script file located...

I spoke too soon. The problem is back.

I just completed the ComboFix and HJT scans.

ComboFix log:

ComboFix 07-11-01.1** - Dillard 2007-11-05 7:22:07.5 - NTFSx86
Microsoft Windows XP Professional 5.1.2600.2.1252.1.1033.18.563...

First, the VundoFix log. This run of VundoFix, like the several others before it, produced no files to delete.

VundoFix V6.5.11

Checking Java version...

Java version is 1.4.2.3
Old...

Oops. I just realized I posted the same file twice. Apologies. Here's the ComboFix log:

ComboFix 07-11-01.1** - Dillard 2007-11-04 7:51:10.4 - NTFSx86
Microsoft Windows XP Professional ...

Hi, and thanks for the response. The HJT file provided in the first post was the entire file (well, except for "Logfile of Trend Micro HijackThis v2.0.2
S," which I inadvertently either didn't copy...

OS: Win XP Media
Symptoms: Explorer.exe shuts down for about 7 seconds, then reappears for about 10 seconds. The cycle repeats. While Explorer.exe is shut down, my Start button, task bar and...