Norton 360

I have Windows 7 and Norton 360 All-in-one Security.  Computer keeps crashing whilst on-line.  Tried to run Norton but it wouldn't open.  Error 8504, 104 message.  Ran Norton Power Eraser and have downloaded latest version.  Still cannot get into Norton 360 and am still getting Error 8504, 104 message.

Help, Please.

Thanks.