My internet download speed is not upto its normal mark. Iam using one computer in a network. All other terminals have their download speed upto mark, but mine is slower than usual. We are using a DSL, and all downloads on my terminal used to go up to the 50s but now they are barely 20s. No antivirus installed, Iam not sure if I have to fix some internet settings or firewall. (Iam also not sure if this is the place to post the problem)?