To potentially solve the issue, first of all, it is recommended to scan your computer using Malwarebytes and Hitman Pro. Usually, they can catch a wide variety of adware viruses. Afterward, I would recommend restarting the PC and doing a scan one more time, as that will assure you that the adware was cleaned. Theoretically, that should help you out, if that doesn't help, you can try scanning your PC additionally with the anti-virus software of your choice.
As for the ads in the browser, they usually keep websites running, but if you want to remove them, either Adblock Plus, Adblock, Ublock or any other plugin both for Chrome and for Firefox should significantly lower the number of ads. In general, I would recommend you to be aware of the links that you are clicking and the files that you are downloading, if you notice something weird or suspicious, it is best to double check or not download at all. Best of luck to you!