When I go to my firefox browser a separate box opens ( X marks-click to finish installing) appears.I close this because I dont know what it is. This though has no effect as it keeps running somehow and enventually a message appears in the bottom left hand corner of the screen-x marks synchronising complete.Then further up the screen another smaller box appears, when this happens my mouse ceases to function and the screen freezes.Any windows open cant be closed and all that can be done is to restart my computer.How do I get rid of this annoyance?