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Cannot Install Forticlient 6.4 or 7.0 on Windows- Invalid Digital Signature

I am trying to Install Forticlient (free version) on a Dell laptop running windows. When I download version 7.0 from the website OR use version 6.4 from my company's files, I get an error code saying "The digital signature on the installation package is invalid. Installation aborted." I tried a couple things already, and nothing has worked so far. I also checked the digital certificate, and it is only valid until 6/16/2021.


Things I've already tried:

1.Restarting computer.

 2.From Internet Options - Select the “Advanced” tab. - Scroll down to the Security section and check the box next to “Allow software to run or install even if the signature is invalid.

3. run-> cmd as administrator ->bcdedit /set nointegritychecks ON

4."Alternatively make sure the Group Policy at Computer Configuration / Administrative Templates / System / Internet Communication Management / Internet Communication settings / Turn off Automatic Root Certificate Update is temporarily Disabled. It can be enabled again after a successful installation. The group policy editor can be started using gpedit.msc. Once the setting has been changed, make sure the group policies are refreshed by running gpupdate.exe /force on the affected machine."

5. Trying to install on a different Dell laptop (need installed on a Dell Latitude 7410, tried on Latitude E7470). The installation gave the same error message on the other laptop. 


Please let me know if there are any possible solutions to this problem. Since I only have the free version, technical support was not able to help me at all. 


What version of Windows are you installing on? If it is a Windows 7 device, then there is a patch necessary to allow Windows 7 to support SHA-2 code signing. If this is the case, more information can be found here on how to patch your device:



Windows 10 version 20H2


Try running as administrator with the /passive switch and log the output. For example:


FortiClientSetup_6.4.4_x64.exe /passive /log c:\temp\FCTexe.log

Update: the installation was able to be completed by re-downloading the exe file after the internet options previously mentioned had been changed. Then, the installation file had to be moved to a different location other than downloads, and then ran. The issue has been resolved.