hjt log

Hi, I'm having some trouble with pop-ups, can anyone tell me what I should fix?

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\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\NORTON~1\navapw32.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\Norton AntiVirus\navapsvc.exe
C:\WINDOWS\System32\nvsvc32.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Common Files\Symantec Shared\Security Center\SymWSC.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\DOCUME~1\Marc\LOCALS~1\Temp\Tijdelijke map 1 voor hijackthis[1].zip\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.yahoo.com/
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.yahoo.com/
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://best-search.us/?page=search&pid=sext01
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,AutoConfigURL = http://pac.pandora.be:8080
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Koppelingen
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: Mega! - {8BC6346B-FFB0-4435-ACE3-FACA6CD77816} - C:\DOCUME~1\Marc\LOCALS~1\Temp\MegaHost.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Program Files\Norton AntiVirus\NavShExt.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\System32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [NAV Agent] C:\PROGRA~1\NORTON~1\navapw32.exe
O4 - HKLM\..\Run: [Share-to-Web Namespace Daemon] C:\Program Files\Hewlett-Packard\HP Share-to-Web\hpgs2wnd.exe
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\System32\\NeroCheck.exe
O4 - HKLM\..\Run: [Symantec NetDriver Monitor] C:\PROGRA~1\SYMNET~1\SNDMon.exe
O4 - HKLM\..\Run: [gcasServ] "C:\Program Files\Microsoft AntiSpyware\gcasServ.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [Skype] "C:\Program Files\Skype\Phone\Skype.exe" /nosplash /minimized
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
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
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=34738&clcid=0x409
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://v5.windowsupdate.microsoft.com/v5consumer/V5Controls/en/x86/client/wuweb_site.cab?1105178141781
O16 - DPF: {C3DFA998-A486-11D4-AA25-00C04F72DAEB} (MSN Photo Upload Tool) - http://sc.groups.msn.com/controls/PhotoUC/MsnPUpld.cab
O16 - DPF: {CC05BC12-2AA2-4AC7-AC81-0E40F83B1ADF} (Live365Player Class) - http://www.live365.com/players/play365.cab