Assuming you have a relatively recent CD-ROM, this is the procedure to install on your Windows Vista computer (similar for Windows 7).
Step 1: Insert the CD-ROM into the CD-ROM drive. The installer should start automatically. You might get this dialog:

Click the "Run WindowsInstall.exe" entry to run the installer.
Step 2: The installer looks for an existing AstroPlanner installation:

If you know there is no installation on the computer, click the Cancel button. You might have to do that a few times to get its attention.
Step 3: Choose the stuff you want to install. By default, the installer will do a complete install, which includes application, catalogues and documentation. All catalogues except the very biggest are selected by default. You might want to change the selections using the checkboxes in the list.

Step 4: IMPORTANT The default folder to install into is (typically) C:\Program Files\. DO NOT INSTALL in that folder. Vista has special protections on that folder which will make AstroPlanner hiccup and crash. Use the Select... button to select an alternative safe folder (we recommend your Documents folder):

Once you've selected the (parent) folder, the installer will show what will be installed and where:

Step 5: Click the Install button. The installer will install all the files in place. This will take a few minutes. It will also put a shortcut to the application on the desktop. Note: it will not put anything into the Start menu.

Step 6: Click Quit to exit from the installer. You can eject the CD-ROM. Note: Look for the version number on the CD-ROM's label. If you did not install the latest version of AstroPlanner V1 (V1.6.1), continue on to download and install the latest version. Otherwise, you are ready to run the application, by clicking the shortcut on your desktop.
This is the procedure to upgrade to the latest version of AstroPlanner (V1.6.1). Note that only the executable application needs updating, although you might also want to download the latest user manual as well.
Step 1: Use your browser to go to the downloads page at http://www.ilangainc.com/astroplanner/reguserdl/. From that page you can download the latest version files:

Step 2: Click the .zip link for the Windows application file (10.4MB download). When you are asked, elect to Save the file:

Navigate to the desktop and click Save:

Step 3: Double-click the downloaded zip file to reveal the application inside:

Step 4: Locate the folder containing the older (previously installed) AstroPlanner application. The easiest way to do this is to right-click the AstroPlanner shortcut that the installer put on your desktop. Choose Open file location to reveal the folder in Windows explorer:

Step 4: Drag the AstroPlanner application icon from the folder revealed in Step 3 to the folder revealed in Step 4:

You will probably be asked if you want to move/copy the file. Click Yes:

When asked if you want to replace the old file with the new file, click Move and Replace:

The application has been updated. Close the Windows Explorer windows and toss the zip file in the trash. You can now run the new version of the application. You might receive this warning:

You'll probably want to uncheck the Always ask before opening this file setting, and click Run. AstroPlanner will always be virus-free, since all development is done on a Mac, which is not susceptible to Windows viruses.