Critical System Protection

I have Norton through Concast. I have on NUMEROUS occasions received a 8504,104 Error message. Power eraser has been ran with minimal sucess. I have had 2 runs from my Windows registry internal system telling me that I have corruption within my system and to get it checked. I also had feedback from Mozilla telling me I had issues with my system. Each time I called Norton and I was reassured that "they were just trying to sell me their product" My system was secure and there was no infections within my system. This is my 4th computer in 1 year so you can understand my anxiety....don't want to buy another one. So my concern is HOW did I get this:  

Ransomware.UkashVirus/FBI Moneypak is a ransomeware alert claiming that your PC is blocked. Once installed,Ukash Virus/FBI Moneypakwill display a scary fake alert stating that your are visiting ilegalwebsits.UkashVirus/FBIMoneypak completeely locks your system so you will not be able to preform any tasks. SetStretch.exe   along with 7 other cookies with double click and goes on.

When I do scans constatntly on my system.            check this address for virus and malware info        http://www.ic3.gov/media/2012/121130.aspx

You'll want to post on the Norton forums as well:

http://community.norton.com/

This particular virus usually comes from visiting a website which has been hacked and is pushing malicious software to users by exploiting a vulnerability in their web browser. Make sure you are up to date on all your patches for your OS and any software that runs on your PC.

You can also run a scan with a second opinion scanner such as malwarebytes or hitman pro

Here are more tools to help in removing infections

https://www-secure.symantec.com/connect/forums/your-system-infected-symantec-tools-help-clear-infection

post your query on Norton forum. the experts there should be able to help you out.

http://community.norton.com/

is the norton functioning correct? have you spoken to tech support?