Windows 7: SLOW network all of a sudden?

It's been like this for a couple days now, and I'm baffled. I RMA'd my ASUS PCE-N13 already, I'm on an N network, and it's faster if I connect through my laptop sharing internet over a cable... I don't have any idea where to start because I've never had this problem before o.O

Call your ISP and see if they are doing some kind of work on the lines in your area or if there are any outages or disruptions that might be causing you slow down.

It's normal on my laptop, my friend's and sister's computers as well...

It could be incorrrect router settings i.e. MTU (Maximum Transfer Units).

and how would one A: find out what the CORRECT router settings are, and B: change it.?

maximum transfer units.... what exactly does that mean and does it vary, and if so, what determining factors are involved? o.O

(not trying to necro this thread, no worries - will start a new one if requested)

I think all these machines are connected to same router(?) and therefore the speedtest posted above is not an ISP bottleneck but a machine to router bottleneck? Although it's a wireless N connection to the router have you noticed a change in signal strength? I would be searching for the fault on your machine. you could check your MTU settings per this link.

Does this happen in Safe mode with Networking?

Some programs affect Internet speed as I found out earlier this year

Your ISP should tell correct settings, if not, here's how.
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To see your present MTU.
Open a command prompt, by typing cmd in the start menu search box, then type:-
netsh interface ipv4 show subinterfaces then press enter.
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To determine your optimum MTU.

Most common ones to try are 1392/1400/1432/1492 (1432 is the usual recommended MTU for Talk Talk but may not work for all).
You can try these ones, or you can diagnose the exact figure yourself as below.
First, log into your router and set MTU to 1500 just for testing purposes.
Open a command prompt. As above.
In the cmd window type: ping -f -l 1472 google.co.uk
(the l is a lower case L, and note there are spaces after ping, f, l, and 1472)
You may get output that says something like "packet needs to fragment but DF set", or 100% packet loss, or “request timed
out”.
If you do, then type that command again, reducing the value of 1472 by small increments until you find the largest number
which works with no lost packets. Then just add 28 to this number to set the MTU in your router settings.
EG: max value with no packet loss = 1464, add 28 = optimum MTU of 1492.
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To change the MTU value in your computer.

Although you may have now entered the right MTU setting in the router, you may need to adjust the MTU in your computer
system, as this may still be showing a default MTU which is different from your router MTU.
You can download Dr TCP which can do this via an easy to use interface, however this does not work for Vista/Windows 7. So this
needs to be done via a command prompt.
Open a command prompt (cmd) run as administrator and type: ipconfig/all
Make a note of the exact names of the network devices.
They are the words directly after “adapter". Eg: “Local Area Connection" or "Wireless Network Connection". now use the
following command to set the MTU value:

Change 1432 to your previously found result if needed.

netsh interface ipv4 set subinterface "Wireless Network Connection" mtu=1432 store=persistent
netsh interface ipv4 set subinterface "Local Area Connection" mtu=1432 store=persistent
-
More details on how to do this at: ::. Kitz - Vista MTU .::

However, if you find that you are getting the “element not found message” when following above instructions, try the below
procedure.
Rather than use the name of the interface, use its numerical ID. To get that ID, enter the following in a command prompt:
netsh interface ipv4 show interfaces
-
Once you know the ID for the interface you want to tweak, use that rather than the description:
netsh interface ipv4 set subinterface “X? mtu=1432 store=persistent (where 'x' is the ID of the interface).
Change 1432 to your previously found result if needed.

What is loopback pseudo-interface 1?

Also, everything is set correctly now, except the router, of which I forgot my password... :/

Sorry I'm not that clever. Looks like you will need to 'Factory Reset' it.