This problem occurs when your “c:Documents and SettingsAll UsersDocuments” directory is read-only, or Windows denies access to the folder for some other reason. In most Windows setups this is not normal.
The simplest workaround is to try the install again, and when the pane to choose file locations comes up, click “Change Directories”. Then, for the tutorial projects directory, change the path to a directory that you know is writable, or create a new one such as “c:PhotoModeler ProjectsTutorials”.
There are a few articles online that discuss this topic. You can find them by doing a Google search for “c:Documents and SettingsAll Users access denied”. Most of the returned links provide some instructions on how to make that directory writable again (as it should be). The simplest solution remains selecting a different directory for the tutorials during the install.