Symptom

When attempting to uninstall FortiClient via Add/Remove Programs or an MDM platform, the uninstaller throws an error similar to:

“The network resource is unavailable” or “Windows Installer cannot find the original package”

This happens because the Windows Installer is looking for the original FortiClient.msi in a path that no longer exists.

Option 1 — Force Uninstall via GUID

Step 1 — Get the product GUID

Open PowerShell as Administrator:

wmic product where "name like 'FortiClient%'" get IdentifyingNumber

Output example: {01CDBF14-709C-4840-B813-DC49A18A943C}

Step 2 — Force uninstall

msiexec /x {YOUR-GUID-HERE} /qn /norestart

Notes:

  • /qn runs silently. Check Task Manager for msiexec.exe to confirm it is running.
  • Remove /qn if you want to see the progress bar.
  • The process can take 1-2 minutes.
  • Restart after uninstall — FortiClient installs WFP network drivers that may not release cleanly without a reboot.

Step 3 — Optional: capture uninstall log

msiexec /x {YOUR-GUID-HERE} /qn /norestart /l*v C:\Temp\forticlient_uninstall.log

Option 2 — Microsoft Fix It Tool

If the GUID method fails, use the Microsoft Program Install and Uninstall Troubleshooter:

  1. Search for “Fix problems that block programs from being installed or removed” on support.microsoft.com.
  2. Download and run it.
  3. Select Uninstall mode and choose FortiClient from the list.

Option 3 — FortiClientCleanupTool

Fortinet’s dedicated cleanup tool removes all traces without relying on the original MSI:

  1. Download FortiClientCleanupTool from support.fortinet.com.
  2. Run as Administrator.
  3. Restart after completion.

Manual Post-Uninstall Cleanup

Run this after confirming FortiClient no longer appears in Programs and Features.

Remove residual folders

Remove-Item "C:\Program Files\Fortinet" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "C:\ProgramData\Fortinet" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "$env:LOCALAPPDATA\Fortinet" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "$env:APPDATA\Fortinet" -Recurse -Force -ErrorAction SilentlyContinue

Remove registry keys

Remove-Item "HKLM:\SOFTWARE\Fortinet" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "HKCU:\Software\Fortinet" -Recurse -Force -ErrorAction SilentlyContinue

Warning: HKLM:\SOFTWARE\Fortinet may contain keys for other Fortinet products. Review with regedit before deleting if unsure.

Restart

Restart the machine. After restarting verify FortiClient no longer appears in Programs and Features and that network connectivity is working normally.

Managed Environments (Intune / SCCM / GPO)

If FortiClient is managed via Intune or SCCM, force uninstalling locally may cause the platform to reinstall it automatically on the next sync.

  • Check for active deployments targeting the device before proceeding.
  • For Intune: Apps > FortiClient > Device install status.
  • Remove the assignment first, then uninstall.

References