I joined Craftsy for the first BOM class last year. After one or two sessions, I noticed a significant slow down. Not sure why, as I have fairly decent internet speed. Made sure my computer and Internet Explorer had all of the updates, still had trouble. Tried to use Firefox, still had issues viewing the video. So I downloaded and installed Google Chrome. Not a single problem, the video's all play wonderfully! If you go to
www.google.com and search for Chrome, you'll find a download and install option. It shouldn't take long, even on a "slower" connection, and you should see improvement.
PS, along with being a "crafty" type, I also work in the computer support field as my day job (which supports my crafting"! I love that my "work" experience is helping me be a better crafty person. Just keeps my life circle intact!
Good Luck with the Craftsy class.