Power Pivot 2010

Sorry that I can't type Chinese in the office.

I just installed powerpivot for excel for the first time. I opened the poewerpivot window and do not see a ribbon with the option for Home and Design. Did something go wrong with my install?
PC operating system: Windows XP Professional 5.1.2600 (Service Pack 3) (32 bit)
Here is link used to download powerpivot 2010. I am using the third one.
http://www.microsoft.com/en-us/download/details.aspx?id=7609
Any guidance would be appreciated