Have to cont,alt,del and bring program to front to be able to click on it, even with 1 program open

Any window, while on internet or not, I have to control, alt, delete, bring to front, close task manager and then I can click on that window, otherwise mouse does not work on that window. Not for selection or drop downs, have to tab from one box to the next on a form. Also, one left click gives the drop down instead of right click. I have checked everything in properties and can't figure it out. It is not in left hand mode.