Also, in the interim, I got antsy, so I ran another malwayrebytes scan. Here's the log:
Malwarebytes' Anti-Malware 1.31
Database version: 1540
Windows 5.1.2600 Service Pack 3
12/25/2008 1:29:37 AM
mbam-log-2008-12-25 (01-29-37).txt
Scan type: Quick Scan
Objects scanned: 67714
Time elapsed: 6 minute(s), 34 second(s)
Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 1
Registry Data Items Infected: 7
Folders Infected: 0
Files Infected: 1
Memory Processes Infected:
(No malicious items detected)
Memory Modules Infected:
(No malicious items detected)
Registry Keys Infected:
(No malicious items detected)
Registry Values Infected:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Framework Windows (Trojan.FakeAlert) -> Quarantined and deleted successfully.
Registry Data Items Infected:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableTaskMgr (Hijack.TaskManager) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop\NoChangingWallpaper (Hijack.DisplayProperties) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\activedesktop\NoChangingWallpaper (Hijack.DisplayProperties) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoSetActiveDesktop (Hijack.DisplayProperties) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoActiveDesktopChanges (Hijack.DisplayProperties) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoSetActiveDesktop (Hijack.DisplayProperties) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoActiveDesktopChanges (Hijack.DisplayProperties) -> Bad: (1) Good: (0) -> Quarantined and deleted successfully.
Folders Infected:
(No malicious items detected)
Files Infected:
C:\WINDOWS\system32\frmwrk32.exe (Trojan.FakeAlert) -> Delete on reboot.
....and now I can change my background and get to my task manager, though the logon bit still doesn't work. I can deal with that though. Thanks for your help, and if you have any more advice, I'd love to hear it.