This is the programme I use to block ads. You will need to select the one for the browser you use (just click on one of the icons to the right of the download button).
https://adblockplus.org/en/internet-explorer
This is the anti-malware programme I use, just click on the FREE download button. Once installed it will ask to update and then give you an option to scan, choose 'Quick Scan'. Once completed anything it has found will appear in a box and you can get rid of them by clicking the 'Fix checked' button.
https://www.malwarebytes.org/
Run Malwarebytes every couple of weeks or so making sure you allow it to update first.
Dave