[Closed] My PC may be infected - I would really appreciate some h

Most of the time my PC seems to be working okay, but then it will slow down considerably and sound very busy even when I am only running a few applications. Perhaps more worrying is that 3 or 4 times in the past few weeks it has shut down and restarted seemingly of its own accord. I have Sygate Personal Firewall, Avast! Online Scanner and SpywareBlaster running. I also perform regular checks with AdAware, Spybot S&D and CWShredder, but they have not discovered anything untoward recently. Please can you help me find out whether there is something in my system that should not be there.

Logfile of HijackThis v1.99.1
Scan saved at 21:07:13, on 01/11/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\csrss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Sygate\SPF\smc.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\Program Files\Java\jre1.6.0_02\bin\jusched.exe
C:\windows\system\hpsysdrv.exe
C:\WINDOWS\system32\hkcmd.exe
C:\WINDOWS\System32\hphmon05.exe
C:\HP\KBD\KBD.EXE
C:\WINDOWS\system32\igfxtray.exe
C:\WINDOWS\system32\spoolsv.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\QuickTime\qttask.exe
C:\WINDOWS\vsnpstd.exe
C:\Program Files\Common Files\Real\Update_OB\realsched.exe
C:\Program Files\Adobe\Photoshop Album Starter Edition\3.0\Apps\apdproxy.exe
C:\WINDOWS\System32\svchost.exe
C:\PROGRA~1\PRESAR~1\Presario\XPHWWRP4\plugin\bin\pchbutton.exe
C:\WINDOWS\system32\wdfmgr.exe
C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
C:\Program Files\SpywareGuard\sgmain.exe
C:\Program Files\SpywareGuard\sgbhp.exe
C:\Program Files\HistoryKill\hkPopupKiller.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\System32\wbem\wmiprvse.exe
C:\WINDOWS\System32\alg.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\SpywareBlaster\spywareblaster.exe
C:\Program Files\Spybot - Search & Destroy\SpybotSD.exe
C:\Documents and Settings\Owner\Desktop\hijackthis[1]\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://qgb10.hpwis.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://srch-qgb10.hpwis.com/
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.ntlworld.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://srch-qgb10.hpwis.com/
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://qgb10.hpwis.com/
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://as.starware.com/dp/search?product=s…&loc=Boston, MA&qry=&url=http://www.ntlworld.com/ (obfuscated)
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://register.hp.com/servlet/WebReg.serv…427A&LF=red
F2 - REG:system.ini: UserInit=C:\WINDOWS\system32\Userinit.exe
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: SpywareBlock Class - {0A87E45F-537A-40B4-B812-E2544C21A09F} - C:\Program Files\SpyCatcher\SCActiveBlock.dll (file missing)
O2 - BHO: SpywareGuard Download Protection - {4A368E80-174F-4872-96B5-0B27DDD11DB2} - C:\Program Files\SpywareGuard\dlprotect.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O3 - Toolbar: Easy-WebPrint - {327C2873-E90D-4c37-AA9D-10AC9BABA46C} - C:\Program Files\Canon\Easy-WebPrint\Toolband.dll
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_02\bin\jusched.exe"
O4 - HKLM\..\Run: [hpsysdrv] c:\windows\system\hpsysdrv.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\WINDOWS\system32\hkcmd.exe
O4 - HKLM\..\Run: [HPHUPD05] c:\Program Files\HP\{45B6180B-DCAB-4093-8EE8-6164457517F0}\hphupd05.exe
O4 - HKLM\..\Run: [HPHmon05] C:\WINDOWS\System32\hphmon05.exe
O4 - HKLM\..\Run: [KBD] C:\HP\KBD\KBD.EXE
O4 - HKLM\..\Run: [UpdateManager] "C:\Program Files\Common Files\Sonic\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [Recguard] C:\WINDOWS\SMINST\RECGUARD.EXE
O4 - HKLM\..\Run: [VTTimer] VTTimer.exe
O4 - HKLM\..\Run: [PS2] C:\WINDOWS\system32\ps2.exe
O4 - HKLM\..\Run: [MediaFace Integration] C:\Program Files\Fellowes\MediaFACE 4.0\SetHook.exe
O4 - HKLM\..\Run: [IgfxTray] C:\WINDOWS\system32\igfxtray.exe
O4 - HKLM\..\Run: [THGuard] "C:\Program Files\TrojanHunter 4.2\THGuard.exe"
O4 - HKLM\..\Run: [SmcService] C:\PROGRA~1\Sygate\SPF\smc.exe -startgui
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [snpstd] C:\WINDOWS\vsnpstd.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Common Files\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [Adobe Photo Downloader] "C:\Program Files\Adobe\Photoshop Album Starter Edition\3.0\Apps\apdproxy.exe"
O4 - HKLM\..\Run: [REGSHAVE] C:\Program Files\REGSHAVE\REGSHAVE.EXE /AUTORUN
O4 - HKCU\..\Run: [Acme.PCHButton] C:\PROGRA~1\PRESAR~1\Presario\XPHWWRP4\plugin\bin\pchbutton.exe
O4 - HKCU\..\Run: [HistoryKill] C:\Program Files\HistoryKill\histkill.exe /startup
O4 - HKCU\..\Run: [HistoryAudit] "C:\Program Files\HistoryAudit\HistoryAudit.exe" /STARTUP
O4 - HKCU\..\Run: [BitTorrent] "C:\Program Files\BitTorrent\bittorrent.exe" –force_start_minimized
O4 - Startup: PowerReg Scheduler V3.exe
O4 - Startup: SpywareGuard.lnk = C:\Program Files\SpywareGuard\sgmain.exe
O4 - Global Startup: Adobe Reader Speed Launch.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O8 - Extra context menu item: Add to Windows &Live Favorites - http://favorites.live.com/quickadd.aspx
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~3\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra button: (no name) - {85d1f590-48f4-11d9-9669-0800200c9a66} - %windir%\bdoscandel.exe (file missing)
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 - {85d1f590-48f4-11d9-9669-0800200c9a66} - %windir%\bdoscandel.exe (file missing)
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://download.bitdefender.com/resources/scan8/oscan8.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftupdat…b?1129821635625
O16 - DPF: {74D05D43-3236-11D4-BDCD-00C04F9A3B61} (HouseCall Control) - http://a840.g.akamai.net/7/840/537/2004061…all/xscan53.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://acs.pandasoftware.com/activescan/as5free/asinst.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/MsnMesse…pDownloader.cab
O16 - DPF: {BB21F850-63F4-4EC9-BF9D-565BD30C9AE9} (a-squared Scanner) - http://ax.emsisoft.com/asquared.cab
O16 - DPF: {EF791A6B-FC12-4C68-99EF-FB9E207A39E6} (McFreeScan Class) - http://download.mcafee.com/molbin/iss-loc/…044/mcfscan.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O20 - Winlogon Notify: igfxcui - C:\WINDOWS\SYSTEM32\igfxsrvc.dll
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: Sygate Personal Firewall (SmcService) - Sygate Technologies, Inc. - C:\Program Files\Sygate\SPF\smc.exe

Thanks,
Si