I have a 4 year old Dell XPS 9000.  I am having difficulties getting PowerPivot to work on it so I expect that something is not quite right, perhaps with an OS file.  I don't have install disk but rather the Dell restore partition.  Is there any way to get this to work so that it doesn't overwrite the existing OS, but rather just does a repair.  I don't want to have to re-install all of the apps.  I don't expect that it will allow me to do this, but I want to make sure.