Is it possible to run both Office 2010 & Office 2013 on the same machine?

I'm having problems installing Office Pro Plus 2013 on my machine. When I install Office 2013 I'm never given a option to do a custom install. When I run the Setup64 file everything installs.

I feel there might be something wrong with my Office 2013 DVD so I called Microsoft. I was told that I can only have Office 2013 installed.

I'm finding this hard to believe because at times I've had 2 versions of Office installed on the same machine.

Thanks,

Paul