Support Number

Causes, Symptoms and Solution to Norton Internet Security error 8506, 421 Error 8506, 421 may occur during installation of a software when Norton Internet security is active or at the time of shutdown or startup of windows.  Norton support phone number. It is important to keep track of when and where did this error appeared. It will make troubleshooting easy. Symptoms The symptoms of the error are as:  Crashes Active Program  PC crashes with error 8506, 421 many times  Error 8506, 421” appears in the center of the screen  Windows start running sluggishly and very slow response to Keyboard and mouse  Computer freezes for a few seconds too often  Causes of Error 8506, 421  Incomplete installation, or corrupt download of Norton Internet security  Corruption in Registry during installation or UN installation  Malware or virus infection may have corrupted Norton security related files or Windows Files.  Norton ...