Laptop totally slow. What could be the problem?

For a few days now, my laptop has been taking a long time to load a page. Even to register somewhere, e.g. Here on Girlfriend, it takes a long time and sometimes nothing happens. What can that be? Does somebody has any idea? I haven't reinstalled anything recently.

If a page takes a long time to load, then this is your internet. Sont just do a virus scan to clean the PC

Maybe a disturbed internet connection?