Why does my internet keep droping my connection?

I can't explain it. At first I thought it was my over-protective anti-virus firewall, but it wasn't because I turned to protection down some and later on I still had this problem. I have Windstream as a internet provider and a Belkin modem. Why does my internet do this?|||Internet usually gives errors for two reasons, firewall and/or modem/router combination. If it isn't your firewall, try on someone else's internet to see if it's your router or modem. There's a very good possibility.