If you need to start Dell SupportAssist driver detection again, even if you did not install all drivers (or installed drivers manually from support webpage) you can do this:
Locate SQlite DB file – C:\ProgramData\SupportAssist\Client\Agent\db\SupportAssist.db
Open the file in SQlite editor – for example: https://sqliteonline.com/
Check table “DriverInstallDetails” ->
SELECT * FROM 'DriverInstallDetails';
It should have list of drivers installed from table “DriverDetails” ->
SELECT * FROM 'DriverDetails';
If not, add rows using ->
INSERT INTO 'DriverInstallDetails' VALUES (%NEXT_ID%, "Installed","0001-01-01 00:00:00",1549184524,"UI",%DRIVER_ID_FROM_
DriverDetails%,null);
Save DB and upload to the directory.
You can scan for drivers again!