I've had a few calls this week about slowness in Google Chrome and Mozilla Firefox. One thing that Chrome and Firefox allow are custom add-ins that let you do stuff like block ads, add toolbars, control your searches, etc.
What you need to be careful with is that many of these programs are malicious in nature. How do you know? If you go to a web-site and it says for example "to track this package, you need to install..." or "to view your map, you need to install...", these are red flags.
To remove in Chrome, click on the three vertical dots in the top right, go to the menu, choose More Tools, and then choose Extensions and remove any programs that don't look legitimate.
Also, if you get pop-up ads in Chrome in the bottom right, they are called notifications, and you've allowed them. Click on the three vertical dots, go to settings, type in Notifications in the search settings, go to site settings, go to notifications and see what you've set to Allow. Click the box to the right and remove what looks goofy.