Strictly speaking, you don't. However, UpSlide will only run if the following prerequisites are already installed on your computer:
- .Net Framework 4.0,
- VSTO runtime 2010 (at least V 10.0.50325).
The installation of the prerequisites requires administrative privileges.
The UpSlide setup will automatically try to detect the prerequisites and, if missing, install them.
Note: the prerequisites can be directly downloaded from
http://www.microsoft.com/download/en/details.aspx?id=17851 for the .Net framework 4.0
and http://go.microsoft.com/fwlink/?LinkId=158918 for the vsto runtime.