Win 8.1 and IE11 is shite - also unstable in that windows in internet explorer freeze as well as not allowing copy/paste functions.
You cant actually uninstall IE11 you have to turn it off in Wndows features on/off.
Again it's control Panel, uninstall programmes and the Turn off windows features by unticking the IE11 box.
I am about to try install IE10 or 9