Reduce the speed of the CPU
If you observe closely, you may see that these stars are shown only against some slides and not all of them.
The stars are just an indication that the particular slide has custom animation. That was you can quickly see at a glance if a slide has content that is animated.
The same star symbol is also shown when the slide itself has any slide transition set.
It really is hard to say because there are many slots and we do not know what your teacher is teaching. I have seen a lot of teachers teaching out of date material. With that said, here is a list from best to worst.
PCI Express x16
PCI Express x1
AGP
PCI
This is list is based on greatest to least and base on the bandwidth read and write speed.
the menu and the toolbars
