These can be left alone and won't cause any problems. The Windows uninstaller takes away all of the Prism program files except for a file containing your serial number and some registry entries.
Any Prism data files you have created will not be removed. To uninstall Prism on Windows manually, click Start → search and open Control Panel → Programs and Features → Uninstall or change a program. On Windows, starting with version 8.0.0, updating Prism automatically uninstalls and replaces the earlier version being updated. Note that the top half is for Windows and the bottom half is for Mac. This page explains how you can remove Prism from your computer.
