Computer shutdown

As I have read on another post, I also experience a system shutdown shortly after starting a scan with either Spybot or Avast 5(.0.507). However, I have yet to have a shutdown during a scan with either Malwarebytes or CCleaner.
Thanks

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 11:41, on 4/17/2010
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v8.00 (8.00.6001.18702)
Boot mode: Normal

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
C:\Program Files\Toshiba\Power Management\CeEPwrSvc.exe
C:\Program Files\TOSHIBA\ConfigFree\CFSvcs.exe
C:\WINDOWS\system32\DVDRAMSV.exe
C:\WINDOWS\system32\svchost.exe
c:\Toshiba\Ivp\Swupdate\swupdtmr.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\TOSHIBA\E-KEY\CeEKey.exe
C:\Program Files\TOSHIBA\Power Management\CePMTray.exe
C:\Program Files\TOSHIBA\TouchPad\TPTray.exe
C:\Program Files\Apoint2K\Apoint.exe
C:\Program Files\EzButton\EzButton.EXE
C:\PROGRA~1\ALWILS~1\Avast5\avastUI.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Common Files\InstallShield\UpdateService\ISUSPM.exe
C:\WINDOWS\system32\RAMASST.exe
C:\Program Files\Apoint2K\Apntex.exe
C:\Program Files\Logitech\MouseWare\system\em_exec.exe
C:\TOSHIBA\IVP\ISM\ivpsvmgr.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Documents and Settings\Gerald T. Barton\My Documents\Downloads\winlogon.scr

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.toshiba.com/search
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://toshibadirect.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://toshibadirect.com/
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = localhost
O2 - BHO: (no name) - {01398B87-61AF-4FFB-9AB5-1A1C5FB39A9C} - (no file)
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: (no name) - {E312764E-7706-43F1-8DAB-FCDD2B1E416D} - (no file)
O4 - HKLM\..\Run: [CeEKEY] C:\Program Files\TOSHIBA\E-KEY\CeEKey.exe
O4 - HKLM\..\Run: [CeEPOWER] C:\Program Files\TOSHIBA\Power Management\CePMTray.exe
O4 - HKLM\..\Run: [TPNF] C:\Program Files\TOSHIBA\TouchPad\TPTray.exe
O4 - HKLM\..\Run: [Apoint] C:\Program Files\Apoint2K\Apoint.exe
O4 - HKLM\..\Run: [EzButton] C:\Program Files\EzButton\EzButton.EXE
O4 - HKLM\..\Run: [Pinger] C:\TOSHIBA\IVP\ISM\pinger.exe /run
O4 - HKLM\..\Run: [Logitech Utility] Logi_MwX.Exe
O4 - HKLM\..\Run: [LogitechVideoRepair] C:\Program Files\Logitech\Video\ISStart.exe
O4 - HKLM\..\Run: [LogitechVideoTray] C:\Program Files\Logitech\Video\LogiTray.exe
O4 - HKLM\..\Run: [avast5] C:\PROGRA~1\ALWILS~1\Avast5\avastUI.exe /nogui
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [Adobe ARM] "C:\Program Files\Common Files\Adobe\ARM\1.0\AdobeARM.exe"
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [ISUSPM] "C:\Program Files\Common Files\InstallShield\UpdateService\ISUSPM.exe" -scheduler
O4 - HKUS\S-1-5-19\..\Run: [TOSCDSPD] C:\Program Files\TOSHIBA\TOSCDSPD\toscdspd.exe (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-19\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-20\..\Run: [TOSCDSPD] C:\Program Files\TOSHIBA\TOSCDSPD\toscdspd.exe (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-18\..\Run: [DWQueuedReporting] "C:\PROGRA~1\COMMON~1\MICROS~1\DW\dwtrig20.exe" -t (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [DWQueuedReporting] "C:\PROGRA~1\COMMON~1\MICROS~1\DW\dwtrig20.exe" -t (User 'Default user')
O4 - Global Startup: RAMASST.lnk = C:\WINDOWS\system32\RAMASST.exe
O8 - Extra context menu item: &AOL Toolbar search - res://C:\Program Files\AOL Toolbar\toolbar.dll/SEARCH.HTML
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\Program Files\Microsoft Office\Office12\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\j2re1.4.2_05\bin\npjpi142_05.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\j2re1.4.2_05\bin\npjpi142_05.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\Program Files\Microsoft Office\Office12\REFIEBAR.DLL
O9 - Extra button: Real.com - {CD67F990-D8E9-11d2-98FE-00C0F0318AFE} - C:\WINDOWS\system32\Shdocvw.dll
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O14 - IERESET.INF: START_PAGE_URL=http://www.toshiba.com
O16 - DPF: {41861299-EAB2-4DCC-986C-802AE12AC499} (RSClientPrint 2005 Class) - https://apecsrpt.jalc.edu/ReportServer/Reserved.ReportViewerWebControl.axd?ExecutionID=0b52a4jyalhkjz45rvb2uy55&ControlID=cf27f8d9c0c7400b9dcbda392ed3fce2&Culture=1033&UICulture=9&ReportStack=1&OpType=PrintCab
O16 - DPF: {CF40ACC5-E1BB-4AFF-AC72-04C2F616BCA7} -
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
O23 - Service: avast! Mail Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
O23 - Service: CeEPwrSvc - COMPAL ELECTRONIC INC. - C:\Program Files\Toshiba\Power Management\CeEPwrSvc.exe
O23 - Service: ConfigFree Service (CFSvcs) - TOSHIBA CORPORATION - C:\Program Files\TOSHIBA\ConfigFree\CFSvcs.exe
O23 - Service: DVD-RAM_Service - Matsushita Electric Industrial Co., Ltd. - C:\WINDOWS\system32\DVDRAMSV.exe
O23 - Service: FLEXnet Licensing Service - Macrovision Europe Ltd. - C:\Program Files\Common Files\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\1050\Intel 32\IDriverT.exe
O23 - Service: stllssvr - Unknown owner - C:\Program Files\Common Files\SureThing Shared\stllssvr.exe (file missing)
O23 - Service: Swupdtmr - Unknown owner - c:\Toshiba\Ivp\Swupdate\swupdtmr.exe

--
End of file - 7534 bytes

Hello.

• Open HijackThis
  
• Choose "Do a system scan only"
  
• Check the boxes in front of these lines:
  
  
  O2 - BHO: (no name) - {01398B87-61AF-4FFB-9AB5-1A1C5FB39A9C} - (no file)
  O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
  O2 - BHO: (no name) - {E312764E-7706-43F1-8DAB-FCDD2B1E416D} - (no file)
  
  
  
• Press "Fix Checked"
  
• Close Hijack This.
  

Please download and run this tool.

Download Malwarebytes' Anti-Malware from Here

Double Click mbam-setup.exe to install the application.

• Make sure a checkmark is placed next to Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
  
• If an update is found, it will download and install the latest version.
  
• Once the program has loaded, select "Perform Quick Scan", then click Scan.
  
• The scan may take some time to finish,so please be patient.
  
• When the scan is complete, click OK, then Show Results to view the results.
  
• Make sure that everything is checked, and click Remove Selected.
  
• When disinfection is completed, a log will open in Notepad and you may be prompted to Restart. (See Note)
  
• The log is automatically saved by MBAM and can be viewed by clicking the Logs tab in MBAM.
  

Note:
If MBAM encounters a file that is difficult to remove, you will be presented with 1 of 2 prompts.
Click OK to either and let MBAM proceed with the disinfection process.
If asked to restart the computer, please do so immediately.

Post the contents of the MBAM Log.