Drivers code 39 after uninstalling Forticlient 6.4.8.1755

[lmfvdesk]

Hello everyone, creating this topic after months and months of search without any positive result.

I am currently in charge of trying to upgrade the 35 last clients we have with VPN 6.4.8.1755

We face a problem that made us stuck for a moment and locked us from upgrading

As soon as we try to touch it, we loose Keyboard Mouse HID and Network (error code 39 object name unknown drive missing or dammaged)

We tried with the same end result : 

- Basic uprade via EMS 

- Manual upgrade via launching different more up to date version of forticlient (EXE or MSI)

- Manual upgrade after uneregistering=>unlocking=> stopping forticlient

- Just uninstalling it via control panel after uneregistering=>unlocking=> stopping forticlient

- uninstalling via msiexec

- Using the FCRemove tool of the right version after uneregistering=>unlocking=> stopping forticlient makes a particular particular case, we notice that Forticlient remains in control panel after reboot and we keep drivers, though we can launch it again as many time as we want it will never full clean, and if we try to remove or upgrade afterward via the other ways, we loose the drivers

If we loose the driver, we get them back by reinstalling VPN 6.4.8.1755, installing another version will not recover the drivers though

After investigating we notice that it seems related to fortifilter.sys  ftvnic.sys or fortiguard

It seems that it does something to keyboard mouse network and hud drivers (some kind of top layer on them?)

After not finding a way to do a clean uninstall, i then focused on trying to restore the driver, but then again only failure :

- uninstalling from device manager then restart

- trying to re add the driver from the assistant in device manager, file doesn't seem missing but not usable

- uninstalling/installing via pnputil

There is one way that worked, uninstalling via Safe Mode without network (it brokes if we use the safe mode with network)

Our problem is, the 35 remaining machines are all other the world, making it really impossible to do by end user (especially with bitlocker key etc)

My question is, did anyone else face the problem because I didn't find a word about it (we excluded the suspicion of conflict with antivirus etc, the uninstall log clearly shows us that it breaks when it removes the fortinet drivers)

And my other question is, do you know either a way to do a step by step uninstall or another way that could help (tried the tools like iObit and Rena but of course same breaking results)

If not do you know a way to restore drivers once they reach this stance, I can provide some logs or extra info if needed of course (800 000 lines logs, I didn't see a way to upload  file so not sure you want me to paste it here ahah)

Hoping to find some suggestions, or even better a solution

With my best regards 

[lmfvdesk]

Well I decided to have another try with a random MSI (7.0.13) and this particular one doesn't touch the drivers and install them afterwards after the restarts, avoiding us the driver explosion

So... problem bypassed :) 

I'm not aware of the closing/archiving of topics let me know If I have to do anything