Most of the problems--including the one involving the dll file upon startup--have gone away. The computer still takes noticeably longer to boot upon startup, but perhaps that's a permanent consequence of the malware now removed? Here is the Malwarebytes log, which shows no infections:
Malwarebytes' Anti-Malware 1.50.1.1100
www.malwarebytes.org
Database version: 5718
Windows 5.1.2600 Service Pack 3
Internet Explorer 8.0.6001.18702
2/9/2011 3:03:54 AM
mbam-log-2011-02-09 (03-03-54).txt
Scan type: Quick scan
Objects scanned: 157206
Time elapsed: 15 minute(s), 57 second(s)
Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 0
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 0
Memory Processes Infected:
(No malicious items detected)
Memory Modules Infected:
(No malicious items detected)
Registry Keys Infected:
(No malicious items detected)
Registry Values Infected:
(No malicious items detected)
Registry Data Items Infected:
(No malicious items detected)
Folders Infected:
(No malicious items detected)
Files Infected:
(No malicious items detected)