Hello Daan, can you check if you can download in firefox safe mode ?

thank you

Hello, thanks for your reply! Unfortunately, the downloads do not work in safe mode either. Do you have any more advice perhaps? Thanks!

Do you have a user.js file in your profile folder ? If you have it, and you are not the creator, it please delete it and check it again.

thank you

The profile folder does not contain such a file, or should there definitely be one? If not, what else can I try? Thanks

It is possible that security software (anti-virus, firewall) is causing the problem. Try to disable security software temporarily to see if that makes a difference.

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Try to create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Hello, thanks for the reply! So a first step (perhaps) towards fixing my problem: in Windows Safe Mode, the downloads work! I also tried your other advices, but the downloads do not work with antivirus and firewall disabled, nor with a new Firefox profile. What can I do now to get the downloads to work in 'normal' Windows as well? Thanks a lot!

Hello everyone! Sorry for replying again, but I really hope someone can help me out! I tried downloading in Windows Safe Mode and it worked, but I still cannot get the downloads to work in 'normal' Windows. I tried downloading with Firewall and Antivirus disabled but that didn't help, is there anything that I can try? Something seems to work in Windows Safe Mode but not in regular mode and it is certainly not my Firewall or Antivirus, what else could it be? Thanks again for all the advice

Note that is you disable AV software via the user interface of this software it is possible that some components are still active in the background and cause issues.

Do a malware check with several malware scanning programs on the Windows computer.

• https://support.mozilla.org/kb/troubleshoot-firefox-issues-caused-malware

Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked