Complete reinstall of your operating system from scratch.  

Backup of current data if possible. 

Erase and clean install windows 10 or 11 ( if your unit is compatible)

Restore data to relevant locations. 

Reinstall required/ supplied programs - MUST be genuine licenses. 

NB - if programs like word and excel are older than 2016 , we would direct you to purchase a more recent version from us as part of the upgrade.