well i tryed to install avast and a alternate firewall but now after trying to install avast my computer just keeps on restarting

Generally, the use of more than one AV (you appear to have Norton AV running)or firewall tool at the same time will not go well as you have found out. The suggested options were offered as exclusive possible choices for cases where neither one of those tools were yet in place on your PC.

You MAY be able to run more than one AV tool but not at the same time. The MS firewall (if enabled) may or may not coexist with another firewall tool but don't be surprised if there are problems.