When I logged into my system, all the tabs on the left have disappeared and I cannot access anything. How do I fix this?
First, your tabs are still there, they are just in a different place. When you shrink the resolution of your screen (make it smaller) the tabs will collapse into a smaller menu in the upper left corner of your screen. If you click on this menu, your tabs will appear, giving you access to all the modules.
Also, if you increase the resolution of your screen (make it bigger) the tabs will automatically appear once again along the left side of your dashboard.
Here is a quick video that will walk you through this: