Ciao a tutti,
ho installato Avira free, ma non mi fa gli aggiornamenti. Dice di aggiornarlo, ma poi resta del tempo in attesa e poi restituisce l'errore 537.
Ho tentato di scaricare AVG free per sostituirlo, ma quando clicco sul download non fa nulla e lo stesso fa se tento di scaricare DrWEB Cure it.
Dopo un tempo lungo di attesa clicco sulla x per uscire dalla disperazione.

Questo è il mio log, potete controllarlo? Grazie infinite.
Logfile of Trend Micro HijackThis v2.0.5
Scan saved at 02:58:18, on 07/09/2015
Platform: Windows 7 SP1 (WinNT 6.00.3505)
MSIE: Internet Explorer v11.0 (11.00.9600.17937)

FIREFOX: 37.0.1 (x86 it)
Boot mode: Normal

Running processes:
C:\Program Files (x86)\Avira\Antivirus\avgnt.exe
C:\Program Files (x86)\Avira\Launcher\Avira.Systray.exe
C:\Program Files (x86)\Internet Explorer\iexplore.exe
C:\Program Files\Sandboxie\32\SbieSvc.exe
C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE
C:\Program Files (x86)\Malwarebytes Anti-Malware\mbam.exe
C:\Users\venom\Desktop\HijackThis.exe

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.virgilio.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/p/?LinkId=255141
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/p/?LinkId=255141
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 =
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files (x86)\Java\jre1.8.0_45\bin\ssv.dll
O2 - BHO: AviraBrowserSafety.BrowserSafety - {c3c77255-42c0-499f-b664-6e981a0b1647} - mscoree.dll (file missing)
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files (x86)\Java\jre1.8.0_45\bin\jp2ssv.dll
O4 - HKLM\..\Run: [avgnt] "C:\Program Files (x86)\Avira\Antivirus\avgnt.exe" /min
O4 - HKLM\..\Run: [Avira SystrayStartTrigger] C:\Program Files (x86)\Avira\Launcher\Avira.SystrayStartTrigger.exe
O4 - HKCU\..\Run: [SandboxieControl] "C:\Program Files\Sandboxie\SbieCtrl.exe"
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVIZIO LOCALE')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVIZIO LOCALE')
O4 - HKUS\S-1-5-19-{ED1FC765-E35E-4C3D-BF15-2C2B11260CE4}-0\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User '?')
O4 - HKUS\S-1-5-19-{ED1FC765-E35E-4C3D-BF15-2C2B11260CE4}-0\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User '?')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVIZIO DI RETE')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVIZIO DI RETE')
O4 - HKUS\S-1-5-20-{ED1FC765-E35E-4C3D-BF15-2C2B11260CE4}-0\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User '?')
O4 - HKUS\S-1-5-20-{ED1FC765-E35E-4C3D-BF15-2C2B11260CE4}-0\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User '?')
O4 - HKUS\S-1-5-21-3051155747-956022163-31990725-1000-{ED1FC765-E35E-4C3D-BF15-2C2B11260CE4}-0\..\Run: [SandboxieControl] "C:\Program Files\Sandboxie\SbieCtrl.exe" (User '?')
O9 - Extra button: Avira Browser Safety - {d8f67242-b229-4065-95fa-391b077ed6ca} - mscoree.dll (file missing)
O11 - Options group: [ACCELERATED_GRAPHICS] Accelerated graphics
O18 - Protocol: abs - {E00957BD-D0E1-4EB9-A025-7743FDC8B27B} - mscoree.dll (file missing)
O23 - Service: Adobe Acrobat Update Service (AdobeARMservice) - Adobe Systems Incorporated - C:\Program Files (x86)\Common Files\Adobe\ARM\1.0\armsvc.exe
O23 - Service: Adobe Flash Player Update Service (AdobeFlashPlayerUpdateSvc) - Adobe Systems Incorporated - C:\Windows\SysWOW64\Macromed\Flash\FlashPlayerUpdateService.exe
O23 - Service: @%SystemRoot%\system32\Alg.exe,-112 (ALG) - Unknown owner - C:\Windows\System32\alg.exe (file missing)
O23 - Service: Avira Mail Protection (AntiVirMailService) - Avira Operations GmbH & Co. KG - C:\Program Files (x86)\Avira\Antivirus\avmailc7.exe
O23 - Service: Avira Pianificatore (AntiVirSchedulerService) - Avira Operations GmbH & Co. KG - C:\Program Files (x86)\Avira\Antivirus\sched.exe
O23 - Service: Avira Real-Time Protection (AntiVirService) - Avira Operations GmbH & Co. KG - C:\Program Files (x86)\Avira\Antivirus\avguard.exe
O23 - Service: Avira Web Protection (AntiVirWebService) - Avira Operations GmbH & Co. KG - C:\Program Files (x86)\Avira\Antivirus\avwebg7.exe
O23 - Service: Avira Service Host (Avira.ServiceHost) - Avira Operations GmbH & Co. KG - C:\Program Files (x86)\Avira\Launcher\Avira.ServiceHost.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: @%SystemRoot%\system32\ieetwcollectorres.dll,-1000 (IEEtwCollectorService) - Unknown owner - C:\Windows\system32\IEEtwCollector.exe (file missing)
O23 - Service: @keyiso.dll,-100 (KeyIso) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: MBAMService - Malwarebytes Corporation - C:\Program Files (x86)\Malwarebytes Anti-Malware\mbamservice.exe
O23 - Service: Mozilla Maintenance Service (MozillaMaintenance) - Mozilla Foundation - C:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe
O23 - Service: @comres.dll,-2797 (MSDTC) - Unknown owner - C:\Windows\System32\msdtc.exe (file missing)
O23 - Service: @%SystemRoot%\System32\netlogon.dll,-102 (Netlogon) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
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: Sandboxie Service (SbieSvc) - Sandboxie Holdings, LLC - C:\Program Files\Sandboxie\SbieSvc.exe
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: TeamViewer 9 (TeamViewer9) - TeamViewer GmbH - C:\Program Files (x86)\TeamViewer\Version9\TeamViewer_Service.exe
O23 - Service: @%SystemRoot%\system32\ui0detect.exe,-101 (UI0Detect) - Unknown owner - C:\Windows\system32\UI0Detect.exe (file missing)
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\Wat\WatUX.exe,-601 (WatAdminSvc) - Unknown owner - C:\Windows\system32\Wat\WatAdminSvc.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 - 8052 bytes

Ciao, il log non presenta problemi.
Questi i miei consigli, Avira ultimamente non è il massimo, AVG è un mattone anche se come AV è valido, avendo Seven io ti consiglio di usare MSE che è sempre fra i meglio, opinione personale, se lo vuoi scaricare vai qui:
http://windows.microsoft.com/it-it/windows/security-essentials-all-versions
Scorri fino alla lingua italiano scegli il tuo S.O. 32 o 64 bit e fai il download, poi esci da internet, elimina avira, fai una pulizia completa con Ccleaner compreso il Registro, per il registro spunta tutte le voci acconsenti al backup quando richiesto, poi installi mse ti colleghi alla rete, lo aggiorni e poi fai una scansione completa del pc.
Fai anche una scansione con Malwarebytes ed elimina quello che trova.
Devi aggiornare Firefox, la tua versione è vecchia ora siamo alla vs. 40.0.3.
Ciao.

Con Seven devi attivare Defender che è già inserito nel Sistema operativo come antispyware e aggiornarlo.
Leggi come fare qui: http://windows.microsoft.com/it-it/windows/turn-windows-defender-on-off#turn-windows-defender-on-off=windows-7
Ciao