OK. Something for you to try. Is your taskbar locked?
Check by right clicking on the bar and if it is there will be a black tick next to "lock the task bar"
If it is locked unlock it by clicking next to the command and look out for some pale vertical dots appearing in the task bar. Left clicking on these dots and holding the click down will allow you to slide the dot (dividers) along. See if this reveals the program buttons. If it does relock the taskbar.