1.       Support of the different platforms and configurations needed?

2.       Does Installation in “clean state” working?

3.       Does the installer is able to calculate needed disk space?

4.       Does the installer capturing the baseline free space before launching the installer?

5.       Does the amount of space the installer claims it needs for the various type of installation is actually taken up or is there any discrepancy?

6.       How much disk space is used by the installer if the installation is quit midway (this would help gathering information on temp files that’s deleted on quitting).

7.       Does the installation recover in case an error is met during the installation?

8.       Does the installer able to Repair any corrupt installation?

9.       If the application installed properly fro each type of installation (for typical, custom and complete)?

10.   Does Installation over network working?

11.   If any file association is made during installation, upon uninstallation, does the association is removed and the base file association is returned to the files?

12.   Does running the installer, followed by launching the program to run some tests, and then running the uninstaller, also return your machine to the base state?

13.   Does uninstallation leave any registry entry, data files in the system?

14.   If there exists a version of the app to be installed already on the machine, does the installer identify that?

15.   Does the installer identify if some needed components (such as, MSDE etc.) are already installed on the system?

16.   Does running two instances of the installer should prompt a message to the user that an installation setup is already running?

17.   If the user logged in, doesn’t have write permission for the machine, how installation reacts to this?  

18.   What happens if the installer tries to install to a directory where there is no write access?

19.   Is the installation path configurable/non configurable?

20.   Check to ensure that when installing the product, it should provide a browse button which enables the user to install at any folder, and it should provide by default folder (For ex: C:\program files)

21.   Is the registering and un-registering the components (dlls) on installation and uninstallation is occurring properly?

22.   Are all the files installed in the respective folders and path?

23.   Whether all the files/registry values/services are installed properly.

24. Check whether the shortcuts are installed properly and also the PATH (any other ENV variables) is updated properly. (It can be CURRENT USERS profile or All Users profile based on your requirements).

25.   Does the installation support, 'UnInstall', 'Modify', 'ReInstall' options?? If yes, does it work?

26.   If the installer is supporting upgrade feature, does it preserve all the necessary settings (mostly user preferences)?

27.   Check for the user privileges before starting installation. (In most of the cases, installer requires ADMIN privileges).

28.   Check the uninstaller entry in add-remove programs. (Check for display string, Display icon and Support information etc.).

29. Does running the installer, and then running the uninstaller, return the machine to the base state?

30.   Reinstallation should, apart from identifying previous versions, also should give an option to Remove and Repair.

31. Check to ensure that license key is properly stored in Windows Registry library.

32.   Check to ensure that if an evaluation version is installed, then a proper message should be displayed when the date of period is expired for evaluation version with proper error message.

33.   Check to ensure that, if Windows Services are installed then it should install in the Services folder of windows directory.

34.   Check to ensure that if any product is installed and it is dependent on some other product, then it should give proper message as "The Product is not installed and it should exit". Check for dependencies.

35.   If the product to be installed uses any third party dll and if it is already installed by some other product confirm that the current installation doesn’t un-register/tamper it and uses the existing one.

36.   If the dll is already there in the system how does the installation work?

37.   And also while uninstalling, check should be made as to whether that the shared dll is left without affecting other product.

38.   “Usability” consideration of the installer.