If it happens when you start your computer have a look at what's being run at start-up with msconfig or Autoruns. It could be some sort of software update or malware etc. Type ' msconfig ' into the Start search box. You can disable an entry by clearing relevant box. Autoruns shows the same information but with much more detail.
UK's best mobile network 2016: best 3G, best 4G, best mobile networks revealed