big problem with start up on gmod

Hi , on gmod when i start up once in a while it will suddenly go black for 2 seconds and than i see my desktop but in the top left corner i see a black box that said ‘‘windows can not load screensaver’’ until i move my curser and i just see my desktop and the gmod simbol in the taskbar, so i try to open it up and it wont let me. i need help from whoever i reading this. or maybe if you have a steam acount we can voice chat about it.