Installation/uninstallation problem

My PDF creator is not working.  I want to uninstall the old version and install a new one, but I am unable to uninstall it.  I get the following message:

There is a problem with this Windows installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor.

It is then following by the message:

Fatal error during installation.

What do I do now?