sorry, which browser are you using?
If you are using Firefox there's an option in the setting for it:
1. click the "burger icon" on the right hand corner
2. Select the "option" button.
3. click the "content" button.
A display like this should show up:
View attachment 128090
Under "Pop-ups". The box, "Block pop-up windows" should be ticked.
If this fails. Try downloading the pop-up from
Free software downloads and software reviews - CNET Download.com
If this fails. Time to wipe your hard-drive clean as suggested by
cinder .
Re-format your whole hard-drive.
It would feel like new again.