Can I install both adobe reader 8.1.2 and foxit reader?

My system have adobe reader 8.1.2 already , but I can’t high light my text and can’t do some functions.So I installed foxit reader. I have not uninstalled the adobe reader 8.1.2 yet. After installed foxit reader, my system sometimes hang (a little bit).
I’d like to know, I have to uninstall the adobe reader??
Please give me kind suggestions asap!!!