See what happens when you download the app. If this occurs an error message, write it down and save it. Try to find out the nature of the problem, using the Internet, Microsoft website or the system help.
Remember what actions you performed with the system previously. Possible problems with the launch emerged because of a conflict with other applications that were installed later. Often open a particular program does not allow the antivirus considers it dangerous for system. In this case, you can try to disable the protection on the app's startup time.
System viruses can also lead to errors when downloading apps. If previously the program was running normally, now maybe it we got a virus that prevents it from opening. Check the start application files antivirus to identify the source of problems.
Make sure the configuration of your computer meets the system requirements necessary for the normal operation of the application. If they are lower, it is possible that this was the cause of the conflict. Typically, a suitable configuration is provided on disk with the app or in the description, if the program downloaded from the Internet.
Update the system drivers. To do this, right-click on the icon "My computer" and select "Properties". Go to the tab "device Manager". Alternately, click on system components and on the Driver tab click "Update". The system will scan the Internet for newer drivers and installs them.
Carefully review the application folder. It can also contain information about additional steps necessary to run the program, special drivers, patches, add-ons and other AIDS.