PROPSYS.dll is not a file that Legacy installs. A Google search of the Internet reveals that PROPSYS.dll problems occur when key operating system files become misconfigured, deleted or damaged.
If the error continues then you can try a system registry repair. There are several utilities available to do this. Some cost money and some are free. We have had success with Ccleaner from Piriform. You can download the free version at http://www.piriform.com/ccleaner/download.