Can I override Internet explorer 11 and use Internet explorer nine also?

[Robert]

[Ben]

Not without a second copy of Windows running in a virtual machine. The rendering engine (the part of the browser that shows the web page) is actually a core piece of Windows. When you install a new version of Internet Explorer, it updates those pieces of Windows too, so even if you still kept the IE 9 program around, websites would still look like they do in IE 11.

If you have a website that requires IE 9 to work, I recommend installing Mozilla Firefox or Google Chrome and keeping IE 9 on the machine. Also, you should pester whoever is in charge of that website to make it work on newer browsers.