How can i know what is being downloaded even without my knowledge?

I find while surfing that a lot of data keeps downloding even if i leave my computer idle. It makes my surfing very slow. I have antivirus and spyware installed and updated. Can any body help please?

How can i know what is being downloaded even without my knowledge?hijackthis

I would suspect that if you have a dial up connection and you have windows update and maybe a few other programs that automatically search and download updates you connection might apear slow. You should look to see what programs are running in your system tray (that area of icons next to your clock) also use the task manager to see what processes are running. You can google the process names to see what they are there for.

If you really want to get technical you can use a program called Wireshark (www.wireshark.org) that would tell you exactly what was being sent and recieved by your computer.

*FYI Wireshark is the new name for a program long known as Ethereal

Unless you are experienced at looking at raw network traffic you might be overwhelmed. You could also use firewall software to block both incoming and outgoing internet connections. Most firewalls can be set to prompt you to allow connections so you would know what is using your bandwidth.

Windows firewall is a bit limited, look for some 3rd party software.

How can i know what is being downloaded even without my knowledge?malware

you can use the ethereal software it can monitor all the TCP / UDP traffic from or into your network card it also analyze the package and you can determine wich application that does the downloading activities so you can chose to shut it down or not