|Try this which I found on the web:|
Right click your Desktop, choose Properties, under the Desktop tab click the Customize Desktop button, under the Web tab make sure that every item is unchecked, click Apply/OK.
There is also a possibility this is a virus, so if the above doesn't help run your AV scans.
If that also doesn't help download, install, update then run the MalwareBytes free version. Let it fix anything it finds.
Please come back and let us know how you got on.