I keep getting a message ' your firewall subscribtion has expired'?

What does the firewall do ?I have norton virus protection and i do the downloads from Microsoft.Do i still need it ?

I keep getting a message ' your firewall subscribtion has expired'?norton 360

A firewall helps protect you from bad guys trying to get into your computer. It sounds like you have Norton firewall and they want more $ from you. In my opinion the best firewall you can get is Zone Alarm, which is free. You can download it, but be sure you don't run more than one firewall at the same time. Windows has a firewall, but it's not very good.

I keep getting a message ' your firewall subscribtion has expired'?photoshop

Yes, every bit helps and you would be amazed at what each part does to help when you don't have it. Try Sygate Personal Firewall or Kerio Personal Firewall or another free one of the sort.
Are you getting this message from norton or windows messenger service? why are you downloading from microsoft? downloads for norton are at symantic.com. but you should just be doing outomatic updates found in the norton program. you should not be going to a site for norton updates. unless your using other types of protection which you should not be doing. use only one becuase they conflict and could cancel out each other without noticing.
The firewall blocks hackers and viruses. You don't need it but its highly recommended.