With automatically generated GUID, on minor version changes, an error
occurred, stating that there is a problem with the installer.
Now, a notification is shown, warning the user that another version of
this product is already installed, and that configuration or removal of
the existing version is possible through Add/Remove Programs on the
Control Panel (expected behavior).

Signed-off-by: Leonid Bloch <leonid@daynix.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>