Is necessary to deinstall openoffice before installing libreoffice in windows 7?
Thank you.
Release Notes - LibreOffice 3.5.5 Final (2012-07-11)
For Windows users that have OpenOffice.org installed, we advise uninstalling that beforehand, because it registers the same file type associations.
But apart of file associations, you can have both installed without troubles, I have three LIbreOffice. plus OOo.
Maybe helpful: → Installing several versions of LibreOffice in parallel / → How to run different OpenOffice.org versions in parallel