Its related to Basic SharPoint SetUp

Question

I have windows ultimate operating sysytem in that already installed Visual studio, Sql and Ms office.

Now i want to install SharePoint 2010, one of my friend said uninstall visual studio, sql and then re-install both for SharePoint.

Now my doubt is Can we re-install visual studio, Sql for SharePoint?

If re-install, tell me the differences.

Thanks in advance!