The numerous popups from den.openpre.net are caused by the activity of adware program on your computer. They may pop up on quite a regular basis in your browser, especially in Google Chrome, Internet Explorer and Mozilla Firefox. Generally, they prompt you to click them, however, clicking doesn’t bring you to good sites. The majority of them is compromised and many infects your system considerably.
It is quite possible that these pop-ups from den.openpre.net may be caused by adware applications like A2zLyrics, LyricsSay, etc. In all cases the penentration of them into your PC took place after you installed some other program downloaded online. There are many of such free applications which users often download from all kinds of online resources. However, the danger is that they’re often bundled with a lot of really useless and unwanted extras like browser hijackers, fake system optimizers, and of course, adwares.
The presence of den.openpre.net popups on your machine really slows it down, especially when it comes to the performance of your affected browsers. Removing this malware is the logical step to which you should come after reading these instructions. Please follow the removal guide developed for you to get rid of this nasty junkware off your PC.