Two quick PowerShell commands to remove Dell SupportAssist — one for the MSI/traditional install, one for the Windows Store app.

# Remove Dell SupportAssist (MSI install)
Uninstall-Package -ProviderName msi -Name 'Dell SupportAssist'

# Remove Dell SupportAssist (Windows Store app)
Get-AppxPackage *SupportAssist* | Remove-AppPackage

Run PowerShell as administrator before executing these commands.