You are looking for a "high quality" free license key for PC HelpSoft Driver Updater. It is a common quest. You have a computer running slow, you’ve found the software that promises to fix it, and you don't want to pay the subscription fee.
Windows Update: Go to Settings > Update & Security > Windows Update. This is the safest method recommended by Microsoft. The Ghost Key: A Guide to "Free" Driver
High-Quality Licence Key: What to Expect Driver Scanning : Identifies outdated drivers
Introducing Helpsoft Driver Updater