Endpoint 12.1 not installing

We have about 10 standalone Windows XP workstations, that we are upgrading to version 12.1x
We have been able too run the wipe tool, too remove the old version, with no issues.

While the majority of the systems, will install 12.1 with no problem, we have 2 systems, that will show that the software has been installed, but it doesn't show up in the " All Programs" start menu.

We are kind of puzzled, since most of these machines were built with the same clone image.

Could it be a patch issue??
Any help would be appreciated.

Ed