My internet has slowed massively in the past 2 hours?

[Chandler]

So, I was downloading a game through Steam at a rate of about 2.4mb/s, But about 2 hours ago it suddenly dropped to 500kb/s and it's taking a long time to load any pages on the Internet. When I reset my router the download speed will return to 2.4mb/s for about 2 minutes before dropping again, Does anybody know what's causing this and if so a fix for it? Thanks.
In response the BenB
I checked the Resource Monitor and I couldn't see anything unusual, I'm sure I get faster download normally because for the past 6 months+ it's been 2.4mb/s, It's just tonight that it seems to have dropped, I'm very confused.

[Lee]

try a better time of day with less traffic or get better broadband.

[Carling]

It looks like your IPS has turned your system band width down, phone them and to see what the problem is,

Advice always download big files at night while your in bed

[BenB]

It's unlikely your ISP is throttling you. Most throttling occurs with uploads. I have a theory but you aren't going to like it.

In most cases of what you are describing the user is infected with malware or a trojan, or even worse a botnet. If this is the cause your for slow speeds, the reason restarting your router may temporarily help is because you are severing the connection with the malware/trojan/botnet host and it's taking time for it to re-establish.

A second theory is that your internet package only provides speeds up to 5mbps(500kB/s). Many providers offer an initial speed boost before dropping down to your subscribed speed.

If you are certain you are not receiving speeds you paid for try opening "Resource Monitor" from within your Start Menu; just type it in the Run box. Select the Network tab and look for anything suspicious. If you do have malware on your system you can try removing it or getting a third party firewall, but either way it needs to go.

Lastly, make sure Windows isn't updating in the background.

[john]

You must have Comcast. I know they give you boost speeds for a certain amount of time, then throttle your connection speed down.

[tumbleweed_biff]

A number of possibilities:
First: malware infection
Second: peer to peer software - torrent software - do you have any of this running?
Third: number of computers on line ... are there multiple computers using your connection? Do you have WiFi running and if so, do you have it encrypted with WPA2 or is it open and therefore accessible to anyone nearby?
Fourth your internet connection: if you have cable modem service then you share bandwidth with your neighbors.
Fifth, Some ISPs offer a burst service to make it so that smaller downloads occur fast but then longer downloads are at a more sedate pace.
Sixth, your download speeds are limited by the outgoing bandwidth of the host.