Please Help

My systen has been changed and I can not get it back. I keep getting a security warning. Here is a text file from Hijack this:
Logfile of HijackThis v1.99.1
Scan saved at 11:14:05 AM, on 9/7/2006
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\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\LEXBCES.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\LEXPPS.EXE
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\Grisoft\AVG Free\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVG Free\avgupsvc.exe
C:\PROGRA~1\Grisoft\AVG Free\avgemc.exe
C:\Program Files\Executive Software\Diskeeper\DkService.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\PCODEC\isamonitor.exe
C:\Program Files\Startup Mechanic\StartupMonitor.exe
C:\PROGRA~1\Grisoft\AVG Free\avgcc.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\PCODEC\isamini.exe
C:\Program Files\C-Organizer Std\C-Organizer.exe
C:\Program Files\ePrompter\ePrompter.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://search.copernic.com/explorer17/?l=ENG&e=
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {202a961f-23ae-42b1-9505-ffe3c818d717} - C:\Program Files\PCODEC\isaddon.dll
O3 - Toolbar: Pa&nicware Pop-Up Stopper Basic - {B1E741E7-1E77-40D4-9FD8-51949B9CCBD0} - C:\Program Files\Panicware\Pop-Up Stopper Basic\popuppro.dll
O3 - Toolbar: &RoboForm - {724d43a0-0d85-11d4-9908-00400523e39a} - C:\Program Files\Siber Systems\AI RoboForm\roboform.dll (file missing)
O3 - Toolbar: Protection Bar - {fe2d25c1-c1db-4b5e-9390-af1cb5302f32} - C:\Program Files\PCODEC\iesplugin.dll
O4 - HKLM\..\Run: [Startup Manager Scanner] C:\Program Files\Startup Mechanic\StartupMonitor.exe
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVG Free\avgcc.exe /STARTUP
O4 - Startup: C-Organizer Std.lnk = C:\Program Files\C-Organizer Std\C-Organizer.exe
O4 - Startup: ePrompter.lnk = C:\Program Files\ePrompter\ePrompter.exe
O4 - User Startup: C-Organizer Std.lnk = C:\Program Files\C-Organizer Std\C-Organizer.exe
O4 - User Startup: ePrompter.lnk = C:\Program Files\ePrompter\ePrompter.exe
O8 - Extra context menu item: Customize Menu - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComCustomizeIEMenu.html
O8 - Extra context menu item: Fill Forms - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O8 - Extra context menu item: Save Forms - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_05\bin\npjpi150_05.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_05\bin\npjpi150_05.dll
O9 - Extra button: Fill Forms - {320AF880-6646-11D3-ABEE-C5DBF3571F46} - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O9 - Extra 'Tools' menuitem: Fill Forms - {320AF880-6646-11D3-ABEE-C5DBF3571F46} - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O9 - Extra button: Save - {320AF880-6646-11D3-ABEE-C5DBF3571F49} - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O9 - Extra 'Tools' menuitem: Save Forms - {320AF880-6646-11D3-ABEE-C5DBF3571F49} - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O9 - Extra button: RoboForm - {724d43aa-0d85-11d4-9908-00400523e39a} - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
O9 - Extra 'Tools' menuitem: RoboForm Toolbar - {724d43aa-0d85-11d4-9908-00400523e39a} - file://C:\Program Files\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
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
O9 - Extra button: (no name) - {D799B0E4-BEDE-41d2-AEE0-1E3A1C4EF918} - C:\Program Files\UnH Solutions\IE Privacy Keeper\PrivacyKeeper.exe (HKCU)
O9 - Extra 'Tools' menuitem: IE Privacy Keeper - {D799B0E4-BEDE-41d2-AEE0-1E3A1C4EF918} - C:\Program Files\UnH Solutions\IE Privacy Keeper\PrivacyKeeper.exe (HKCU)
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {B1826A9F-4AA0-4510-BA77-9013E74E4B9B} - http://www.trendmicro.com/spyware-scan/as4web.cab
O16 - DPF: {B8BE5E93-A60C-4D26-A2DC-220313175592} (ZoneIntro Class) - http://cdn2.zone.msn.com/binFramewor...o.cab34246.cab
O16 - DPF: {E8F628B5-259A-4734-97EE-BA914D7BE941} (Driver Agent ActiveX Control) - http://driveragent.com/files/driveragent.cab
O23 - Service: ASP.NET Admin Service (aspnet_admin) - Unknown owner - C:\WINDOWS\Microsoft.NET\Framework\v2.0.40607\aspn et_admin.exe (file missing)
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG Free\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG Free\avgupsvc.exe
O23 - Service: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG Free\avgemc.exe
O23 - Service: Diskeeper - Executive Software International, Inc. - C:\Program Files\Executive Software\Diskeeper\DkService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: LexBce Server (LexBceS) - Lexmark International, Inc. - C:\WINDOWS\system32\LEXBCES.EXE
O23 - Service: ProgramCheckerPro (sassvc) - Unknown owner - C:\Program Files\Zenturi\ProgramChecker\sassvc.exe

Any help appreciated