I know I found this in the Archive thread, but I found myself with the same problem as the OP:

"Security warning: your computer may be infected with harmful or unwanted software!
HELLO experts..

I recently got this pop up problem on my computer, it closes my the first window of my browser whenever i open a new one, and a red icon with a "!" in the middle saying "Security warnng: your coputer may be infected with harmful or unwanted software!"

ive done pretty much everything, ad-aware/norton and other anti virus programs,but nothing seems t work....im begging please someone help..
this is super furstrating..

thank you in advance"

Here's my Hijackthis 1.99 log:

Logfile of HijackThis v1.99.1
Scan saved at 11:12:30 PM, on 12/19/2006
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.5730.0011)

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:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\PROGRA~1\COMMON~1\AOL\ACS\acsd.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
C:\WINDOWS\system32\devldr32.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\System32\CTsvcCDA.EXE
C:\WINDOWS\System32\E_S00RP1.EXE
C:\Program Files\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
C:\WINDOWS\System32\nvsvc32.exe
C:\Program Files\Prevx1\PXAgent.exe
C:\Program Files\Dell\Support\Alert\bin\DAMon.exe
C:\Program Files\Common Files\Symantec Shared\ccApp.exe
C:\Program Files\MUSICMATCH\MUSICMATCH Jukebox\mmtask.exe
C:\Program Files\Java\jre1.5.0_09\bin\jusched.exe
C:\WINDOWS\system32\hostspool32.exe
C:\Program Files\Roxio\Easy CD Creator 5\DirectCD\DirectCD.exe
C:\PROGRA~1\PESTPA~1\PPControl.exe
C:\PROGRA~1\PESTPA~1\PPMemCheck.exe
C:\PROGRA~1\PESTPA~1\CookiePatrol.exe
C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_S4I2S1.EXE
C:\WINDOWS\system32\RUNDLL32.EXE
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe
C:\Program Files\Prevx1\PXConsole.exe
C:\Program Files\YourWare Solutions\FreeRAM XP Pro\FreeRAM XP Pro.exe
C:\WINDOWS\system32\hostspool32.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Spyware Doctor\swdoctor.exe
C:\Program Files\Spyware Doctor\sdhelp.exe
C:\PROGRA~1\NORTON~2\SPEEDD~1\nopdb.exe
C:\Program Files\Common Files\Microsoft Shared\Works Shared\wkcalrem.exe
C:\WINDOWS\System32\SAgent4.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\WINDOWS\System32\msiexec.exe
C:\Program Files\Adobe\Acrobat 5.0\Reader\AcroRd32.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Documents and Settings\David Thoren Jr\Desktop\hijackthis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.dellnet.com
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.yahoo.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
R1 - HKLM\Software\Microsoft\Internet Explorer\SearchURL,(Default) = about:blank
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O2 - BHO: Malicious Scripts Scanner - {55EA1964-F5E4-4D6A-B9B2-125B37655FCB} - C:\Documents and Settings\All Users\Application Data\Prevx\pxbho.dll
O2 - BHO: SafeGuard Protect PCShield - {564FFB73-9EEF-4969-92FA-5FC4A92E2C2A} - C:\WINDOWS\System32\sfg_0138.dll
O2 - BHO: PCTools Site Guard - {5C8B2A36-3DB1-42A4-A3CB-D426709BBFEB} - C:\PROGRA~1\SPYWAR~1\tools\iesdsg.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O2 - BHO: PCTools Browser Monitor - {B56A7D7D-6927-48C8-A975-17DF180C71AC} - C:\PROGRA~1\SPYWAR~1\tools\iesdpb.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\System32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [UpdReg] C:\WINDOWS\Updreg.exe
O4 - HKLM\..\Run: [AHQInit] C:\Program Files\Creative\SBLive\Program\AHQInit.exe
O4 - HKLM\..\Run: [Dell|Alert] C:\Program Files\Dell\Support\Alert\bin\DAMon.exe
O4 - HKLM\..\Run: [IMJPMIG8.1] C:\WINDOWS\IME\imjp8_1\IMJPMIG.EXE /Spoil /RemAdvDef /Migration32
O4 - HKLM\..\Run: [IMEKRMIG6.1] C:\WINDOWS\ime\imkr6_1\IMEKRMIG.EXE
O4 - HKLM\..\Run: [MSPY2002] C:\WINDOWS\System32\IME\PINTLGNT\ImScInst.exe /SYNC
O4 - HKLM\..\Run: [PHIME2002ASync] C:\WINDOWS\System32\IME\TINTLGNT\TINTSETP.EXE /SYNC
O4 - HKLM\..\Run: [PHIME2002A] C:\WINDOWS\System32\IME\TINTLGNT\TINTSETP.EXE /IMEName
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [ccRegVfy] "C:\Program Files\Common Files\Symantec Shared\ccRegVfy.exe"
O4 - HKLM\..\Run: [mmtask] C:\Program Files\MUSICMATCH\MUSICMATCH Jukebox\mmtask.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.5.0_09\bin\jusched.exe"
O4 - HKLM\..\Run: [Identifier] hostspool32.exe
O4 - HKLM\..\Run: [AdaptecDirectCD] C:\Program Files\Roxio\Easy CD Creator 5\DirectCD\DirectCD.exe
O4 - HKLM\..\Run: [DeadAIM] rundll32.exe "C:\Program Files\AIM95\\DeadAIM.ocm",ExportedCheckODLs
O4 - HKLM\..\Run: [CloneCDTray] "C:\Program Files\SlySoft\CloneCD\CloneCDTray.exe" /s
O4 - HKLM\..\Run: [PestPatrol Control Center] C:\PROGRA~1\PESTPA~1\PPControl.exe
O4 - HKLM\..\Run: [PPMemCheck] C:\PROGRA~1\PESTPA~1\PPMemCheck.exe
O4 - HKLM\..\Run: [CookiePatrol] C:\PROGRA~1\PESTPA~1\CookiePatrol.exe
O4 - HKLM\..\Run: [PCShield] regsvr32 /s "C:\WINDOWS\System32\sfg_0138.dll"
O4 - HKLM\..\Run: [EPSON Stylus C66 Series] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_S4I2S1.EXE /P23 "EPSON Stylus C66 Series" /O6 "USB002" /M "Stylus C66"
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\System32\NeroCheck.exe
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\System32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [CTDrive] rundll32.exe C:\WINDOWS\system32\drvvan.dll,startup
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [SpyHunter] C:\Program Files\Enigma Software Group\SpyHunter\SpyHunter.exe
O4 - HKLM\..\Run: [PrevxOne] "C:\Program Files\Prevx1\PXConsole.exe"
O4 - HKCU\..\Run: [PCShield] regsvr32 /s "C:\WINDOWS\System32\sfg_0138.dll"
O4 - HKCU\..\Run: [Microsoft Works Update Detection] C:\Program Files\Microsoft Works\WkDetect.exe
O4 - HKCU\..\Run: [FreeRAM XP] "C:\Program Files\YourWare Solutions\FreeRAM XP Pro\FreeRAM XP Pro.exe" -win
O4 - HKCU\..\Run: [Identifier] hostspool32.exe
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [Spyware Doctor] "C:\Program Files\Spyware Doctor\swdoctor.exe" /Q
O4 - Global Startup: Adobe Gamma Loader.lnk = C:\Program Files\Common Files\Adobe\Calibration\Adobe Gamma Loader.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office\OSA9.EXE
O4 - Global Startup: Microsoft Works Calendar Reminders.lnk = ?
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Restrictions present
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O8 - Extra context menu item: Liatro SWF Decoder Catch - C:\Program Files\Liatro\Liatro SWF Tools 4.6\swfcatch.htm
O9 - Extra button: Spyware Doctor - {2D663D1A-8670-49D9-A1A5-4C56B4E14E84} - C:\PROGRA~1\SPYWAR~1\tools\iesdpb.dll
O11 - Options group: [INTERNATIONAL] International*
O15 - Trusted Zone: http://s1.cgi.gamefaqs.com
O15 - Trusted Zone: http://s2.cgi.gamefaqs.com
O15 - Trusted Zone: http://*.gamefaqs.com
O16 - DPF: {C5E28B9D-0A68-4B50-94E9-E8F6B4697514} (NsvPlayX Control) - http://www.nullsoft.com/nsv/embed/nsvplayx_vp3_mp3.cab
O18 - Protocol: ms-help - {314111C7-A502-11D2-BBCA-00C04F8EC294} - C:\Program Files\Common Files\Microsoft Shared\Help\hxds.dll
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\
O23 - Service: AOL Connectivity Service (AOL ACS) - America Online, Inc. - C:\PROGRA~1\COMMON~1\AOL\ACS\acsd.exe
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
O23 - Service: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Password Validation Service (ccPwdSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccPwdSvc.exe
O23 - Service: Creative Service for CDROM Access - Creative Technology Ltd - C:\WINDOWS\System32\CTsvcCDA.EXE
O23 - Service: EPSON V3 Service2(03) (EPSON_PM_RPCV2_01) - SEIKO EPSON CORPORATION - C:\WINDOWS\System32\E_S00RP1.EXE
O23 - Service: Freenet 0.7 darknet-8888 (freenet-darknet-8888) - Unknown owner - C:\Program Files\Freenet\bin\wrapper-windows-x86-32.exe" -s "C:\Program Files\Freenet\wrapper.conf (file missing)
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: iPod Service - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Norton AntiVirus Auto Protect Service (navapsvc) - Symantec Corporation - C:\Program Files\Norton SystemWorks\Norton AntiVirus\navapsvc.exe
O23 - Service: Norton Unerase Protection (NProtectService) - Symantec Corporation - C:\Program Files\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\System32\nvsvc32.exe
O23 - Service: Prevx Agent (PREVXAgent) - Unknown owner - C:\Program Files\Prevx1\PXAgent.exe" -f (file missing)
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\COMMON~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: PC Tools Spyware Doctor (SDhelper) - PC Tools Research Pty Ltd - C:\Program Files\Spyware Doctor\sdhelp.exe
O23 - Service: Speed Disk service - Symantec Corporation - C:\PROGRA~1\NORTON~2\SPEEDD~1\nopdb.exe
O23 - Service: Epson Printer Status Agent4 (StatusAgent4) - SEIKO EPSON CORPORATION - C:\WINDOWS\System32\SAgent4.exe