You can complete most failed installations with a restart and a reinstallation. The installation log is stored in the %Temp% directory. In the installation log, search for "return value 3". The lines preceding this value should contain an error message regarding the failure. If the error message identifies the problem (for example, an invalid product key), you should be able to resolve it. For more complex problems, you may need to contact Symantec support or do a manual cleanup of the installation.