If you are going to stick with the older version of Microsoft Office then by all means; uninstall 2007, no need to have an application on your harddrive which is taking up 400 plus Megabytes of space and that you won't be using.
Please remember to set a restore point before uninstalling Office 2007.
Let's take this a step further; If you are not already familiar with "Open Office.org" Go Here: http://www.openoffice.org/
to learn everything you need to know about a wonderful and free!
substitute for Microsoft Office.
It is free! It is constantly being upgraded and all future upgrades are free AND
it is compatible with all versions of Microsoft Office and all other major office applications.
You will never have to pay several hundreds of dollars for office applications again and any document or file created in Microsoft office (any version) will open in and can be used with "Open Office".
I use it on one of my computers and when I get as comfortable with it as I am with Ms office I will download onto all my confusers.
Check it out! If you do well or even just ok with Ms Office it won't take you long to aquire the learning curve.