offline trotz bestehender Internetverbindung

Hallo,
mein router, speedport w503v, ist ständig auf online eingestellt. wenn ich firefox durch systemstart hochfahre, meldet dieser häufig "offline", d.h. die internetverbindung wird irgendwie nicht erkannt. manchmal klappt es doch. wenn ich den router aus- und wiederanschalte, geht firefox online.
woran kann das liegen?

den offline-Haken habe ich habe ich immer gleich entfernt und dann wiederholt. Das brachte aber kein Ergebnis.
Ich werde wie von brummelchen empfohlen "hijackthis" ausführen und ihm zusenden. Danke.

Habe Firefox nicht im Systemstart.
Hier der Logogfile von HJT:
Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16:52:03, on 04.07.2010
Platform: Unknown Windows (WinNT 6.01.3504)
MSIE: Internet Explorer v8.00 (8.00.7600.16385)
Boot mode: Normal

Running processes:
C:\Program Files (x86)\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Program Files (x86)\McAfee Security Scan\2.0.181\SSScheduler.exe
C:\Program Files (x86)\Sun\StarOffice 9\program\soffice.exe
C:\Program Files (x86)\Sun\StarOffice 9\program\soffice.bin
C:\Program Files (x86)\Common Files\Java\Java Update\jusched.exe
C:\Program Files (x86)\Avira\AntiVir Desktop\avgnt.exe
C:\Program Files (x86)\HiYo\Bin\HiYo.exe
C:\Program Files (x86)\Mozilla Firefox\firefox.exe
C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe
C:\Program Files (x86)\Mozilla Firefox\plugin-container.exe
C:\Program Files (x86)\Trend Micro\HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://homepage.packardbell.com/rdr.aspx?b=ACP…f5v135y4891045n
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://mystart.incredimail.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://homepage.packardbell.com/rdr.aspx?b=ACP…f5v135y4891045n
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://homepage.packardbell.com/rdr.aspx?b=ACP…f5v135y4891045n
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page = C:\Windows\SysWOW64\blank.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
F2 - REG:system.ini: UserInit=userinit.exe
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files (x86)\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: Search Helper - {6EBF7485-159F-4bff-A14F-B9E3AAC4465B} - C:\Program Files (x86)\Microsoft\Search Enhancement Pack\Search Helper\SEPsearchhelperie.dll
O2 - BHO: Windows Live Anmelde-Hilfsprogramm - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - C:\Program Files (x86)\Google\Google Toolbar\GoogleToolbar_32.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files (x86)\Google\GoogleToolbarNotifier\5.5.4723.1820\swg.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files (x86)\Java\jre6\bin\jp2ssv.dll
O2 - BHO: Windows Live Toolbar Helper - {E15A8DC0-8516-42A1-81EA-DC94EC1ACF10} - C:\Program Files (x86)\Windows Live\Toolbar\wltcore.dll
O3 - Toolbar: &Windows Live Toolbar - {21FA44EF-376D-4D53-9B0F-8A89D3229068} - C:\Program Files (x86)\Windows Live\Toolbar\wltcore.dll
O3 - Toolbar: Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files (x86)\Google\Google Toolbar\GoogleToolbar_32.dll
O3 - Toolbar: TerraTec Home Cinema - {AD6E6555-FB2C-47D4-8339-3E2965509877} - C:\PROGRA~2\TerraTec\TERRAT~1\THCDES~1.DLL
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files (x86)\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [StartCCC] "C:\Program Files (x86)\ATI Technologies\ATI.ACE\Core-Static\CLIStart.exe" MSRun
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files (x86)\Common Files\Java\Java Update\jusched.exe"
O4 - HKLM\..\Run: [avgnt] "C:\Program Files (x86)\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKLM\..\Run: [Hiyo] C:\Program Files (x86)\HiYo\bin\HiYo.exe /RunFromStartup
O4 - HKCU\..\Run: [swg] "C:\Program Files (x86)\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe"
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'LOKALER DIENST')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'LOKALER DIENST')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'NETZWERKDIENST')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'NETZWERKDIENST')
O4 - Startup: StarOffice 9.lnk = C:\Program Files (x86)\Sun\StarOffice 9\program\quickstart.exe
O4 - Global Startup: McAfee Security Scan Plus.lnk = ?
O8 - Extra context menu item: add to &BOM - C:\\PROGRA~2\\BIET-O~1\\\\AddToBOM.hta
O8 - Extra context menu item: Add to Google Photos Screensa&ver - res://C:\Windows\system32\http://GPhotos.scr/200
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~2\MICROS~1\Office12\http://EXCEL.EXE/3000
O8 - Extra context menu item: Google Sidewiki... - res://C:\Program Files (x86)\Google\Google Toolbar\Component\GoogleToolbarDynamic_mui_en_96D6FF0C6D236BF8.dll/cmsidewiki.html
O9 - Extra button: In Blog veröffentlichen - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: In Windows Live Writer in Blog veröffentliche&n - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O13 - Gopher Prefix:
O23 - Service: Adobe Active File Monitor V7 (AdobeActiveFileMonitor7.0) - Adobe Systems Incorporated - c:\Program Files (x86)\Adobe\Photoshop Elements 7.0\PhotoshopElementsFileAgent.exe
O23 - Service: @%SystemRoot%\system32\Alg.exe,-112 (ALG) - Unknown owner - C:\Windows\System32\alg.exe (file missing)
O23 - Service: AMD External Events Utility - Unknown owner - C:\Windows\system32\atiesrxx.exe (file missing)
O23 - Service: Avira AntiVir MailGuard (AntiVirMailService) - Avira GmbH - C:\Program Files (x86)\Avira\AntiVir Desktop\avmailc.exe
O23 - Service: Avira AntiVir Planer (AntiVirSchedulerService) - Avira GmbH - C:\Program Files (x86)\Avira\AntiVir Desktop\sched.exe
O23 - Service: Avira AntiVir Guard (AntiVirService) - Avira GmbH - C:\Program Files (x86)\Avira\AntiVir Desktop\avguard.exe
O23 - Service: Avira AntiVir WebGuard (AntiVirWebService) - Avira GmbH - C:\Program Files (x86)\Avira\AntiVir Desktop\AVWEBGRD.EXE
O23 - Service: @%SystemRoot%\system32\efssvc.dll,-100 (EFS) - Unknown owner - C:\Windows\System32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\fxsresm.dll,-118 (Fax) - Unknown owner - C:\Windows\system32\fxssvc.exe (file missing)
O23 - Service: FLEXnet Licensing Service - Macrovision Europe Ltd. - C:\Program Files (x86)\Common Files\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: ForceWare Intelligent Application Manager (IAM) - Unknown owner - C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin32\nSvcAppFlt.exe
O23 - Service: GRegService (Greg_Service) - Acer Incorporated - C:\Program Files (x86)\Packard Bell\Registration\GregHSRW.exe
O23 - Service: Google Update Service (gupdate) (gupdate) - Google Inc. - C:\Program Files (x86)\Google\Update\GoogleUpdate.exe
O23 - Service: Google Software Updater (gusvc) - Google - C:\Program Files (x86)\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: @keyiso.dll,-100 (KeyIso) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: McAfee Security Scan Component Host Service (McComponentHostService) - McAfee, Inc. - C:\Program Files (x86)\McAfee Security Scan\2.0.181\McCHSvc.exe
O23 - Service: @comres.dll,-2797 (MSDTC) - Unknown owner - C:\Windows\System32\msdtc.exe (file missing)
O23 - Service: Nero BackItUp Scheduler 4.0 - Nero AG - C:\Program Files (x86)\Common Files\Nero\Nero BackItUp 4\NBService.exe
O23 - Service: @%SystemRoot%\System32\netlogon.dll,-102 (Netlogon) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: ForceWare IP service (nSvcIp) - Unknown owner - C:\Program Files\NVIDIA Corporation\NetworkAccessManager\bin32\nSvcIp.exe
O23 - Service: @%systemroot%\system32\psbase.dll,-300 (ProtectedStorage) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\Locator.exe,-2 (RpcLocator) - Unknown owner - C:\Windows\system32\locator.exe (file missing)
O23 - Service: @%SystemRoot%\system32\samsrv.dll,-1 (SamSs) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%SystemRoot%\system32\snmptrap.exe,-3 (SNMPTRAP) - Unknown owner - C:\Windows\System32\snmptrap.exe (file missing)
O23 - Service: @%systemroot%\system32\spoolsv.exe,-1 (Spooler) - Unknown owner - C:\Windows\System32\spoolsv.exe (file missing)
O23 - Service: @%SystemRoot%\system32\sppsvc.exe,-101 (sppsvc) - Unknown owner - C:\Windows\system32\sppsvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\ui0detect.exe,-101 (UI0Detect) - Unknown owner - C:\Windows\system32\UI0Detect.exe (file missing)
O23 - Service: Updater Service - Acer - C:\Program Files\Packard Bell\Packard Bell Updater\UpdaterService.exe
O23 - Service: @%SystemRoot%\system32\vaultsvc.dll,-1003 (VaultSvc) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%SystemRoot%\system32\vds.exe,-100 (vds) - Unknown owner - C:\Windows\System32\vds.exe (file missing)
O23 - Service: @%systemroot%\system32\vssvc.exe,-102 (VSS) - Unknown owner - C:\Windows\system32\vssvc.exe (file missing)
O23 - Service: @%systemroot%\system32\wbengine.exe,-104 (wbengine) - Unknown owner - C:\Windows\system32\wbengine.exe (file missing)
O23 - Service: @%Systemroot%\system32\wbem\wmiapsrv.exe,-110 (wmiApSrv) - Unknown owner - C:\Windows\system32\wbem\WmiApSrv.exe (file missing)
O23 - Service: @%PROGRAMFILES%\Windows Media Player\wmpnetwk.exe,-101 (WMPNetworkSvc) - Unknown owner - C:\Program Files (x86)\Windows Media Player\wmpnetwk.exe (file missing)

--
End of file - 10346 bytes

Kann das leider nicht selbst analysieren. Hoffe auf Eure Expertise. Dank im voraus.

Hallo Heaven-69,
HJT 2.0.4 habe ich heruntergeladen und gestartet. Es kommt jedoch eine Fehlermeldung, dass ich in der "host" Datei etwwas verändern muss. Mir ist jedoch nicht klar was. Hier der Inhalt der Datei:
# Copyright (c) 1993-2009 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host

# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost

Erbitte helfenden Hinweis. Danke.