Hi Liam,

Google does a pretty good job about keeping pop-up windows under control in its Chrome browser.
But still if you are getting many ads, then you can follows the below steps to clean up your browser:

Enable Chrome's Pop-Up Blocking Feature

1. Click on the Chrome menu icon in the upper-right corner of the browser, and then click on Settings.


2. Click on the Show Advanced Settings link at the bottom.


3. Scroll down to the Privacy header and click on the big Content Settings button.


4. Scroll down a little bit more in the window that appears until you see the Pop-ups section. The option “Do not allow any site to show pop-ups” should be selected; if it isn’t select it. Click Done.

Check Your Approved List of Sites

1. Follow steps 1 to 3 above.
2. Scroll down to Pop-Ups and click on the large “Manage exceptions” button.

3. If there are any entries in the ensuing window, move your mouse to the far right of each row until an X appears. Click that X. Click Done.

Install an Ad-Blocking Extension

1. Click the Menu button on the top right and click Settings.



2. Click Extensions on the top left and click Get More Extensions.


3. Search for an ad-blocker such as Adblock Plus and click Free to install.


4. Set the ad-blocker up to block Malware as well as pop-ups during the configuration. With Adblock Plus you also can nuke social media buttons and prevent sites (and ad companies) from tracking that which you do on the Web. You can also click on the icon in your Chrome browser to customize Adblock Plus to a greater degree, if you so desire.

Uninstall Odd Software

1. Go to your Windows Control Panel and click Uninstall a Program.
2. Click the Add/Remove programs link (or Programs and Features, depending on what version of Windows you’re running). 
Perhaps an app that you accidentally installed as a package deal alongside an app that you actually wanted, a strange game-sounding program that’s appeared out of nowhere, or anything that just doesn’t sound quite right.
If you don’t recognize an app that you have installed, you might want to consider uninstalling it – it could be the source of your pop-up problems.



I hope this helps.

Regards,
Lokesh