registry errors is not what would slow your machine. More likely it is installed software that accesses the internet for updates such Google Chrome, windows updates, printer software, anti-virus software, or you could even have a virus.
There was at least one recent windows update that slowed this laptop to a crawl. I restored to an old restore point & disabled updates and now it runs as before. Sometimes it is better to live w/o an update then to accept the slowdown it causes.