I have a cable internet with a belkin router, also I have connected a laptop upstairs to it with a usb cord so I can do my work but the laptop keeps freezing.

the usb network adapter probably isn't working properly without drivers.You should be able to get the the drivers for your model adapter at the belkin website under support. Then if your laptop is lacking a cd drive you can just load the drivers on to thumb drive and install them from there. I hope i was able to help.

1. Please check your computer's IP address should be autamatic.

2. Please do not connect your cable from your computer to Belkin's Internet port

3. Please connect your cable between your computer to belkin router's 1,2,3 or 4 number's port

4. Please check you cable should be not cross cable.

Step 1 : Connect modem - Router - Computer ( Wired )
Step 2 : Open router setup by typing http://192.168.2.1 on the address bar of internet explorer
Step 3 : On the left side under internet WAN click Connection Type
Step 4 : leave the Password Blank and click submit
Step 5 : Choose the connection type as dynamic and click next
Step 6 : Leave the Host name blank and click apply
Step 7 : On the left Under Internet WAN Click MAC Address
Step 8 : Click Clone and Click Apply changes
Step 9 : If the Internet status on the top right is connected
Step 10 : Then check if you have internet
Step 11 : if not Then unplug the Power Cable from the Modem And the Router
Step 12 : Plug the power Cord to the Modem
Step 13 : Wait till all the lights are on
Step 14 : Plug the power to the belkin
Step 15 : Check the color of the light in the belkin
Step 16 :If green then Check if you have internet
If not working then call belkin

The upstairs computer is wired or wireless ?

If the upstairs computer is working then the router must be working properly.
Check the connection between the downstairs computer and the router.
If it is a wireless computer then check the wireless connection status on that computer.
Click Here for step by step solution

No. You'll need to run a "cross-over" Ethernet cable from one of the "LAN" ports on the "downstairs" router, connecting to the "WAN" port on another router that you will need to buy, and place "upstairs", and connect the 4 devices to the 4 "LAN" ports.

Or, run a long "straight-through" Ethernet cable from your DSL-modem (or cable-modem) that is "downstairs", and move your wireless router "upstairs", and connect the 4 devices to the router's "LAN" ports.
Your laptop "downstairs" should still be able to connect (wirelessly) to the wireless-router that is "upstairs".

Try using 128 bit hex code. You put in a passphrase and it will scramble it into 13 pairs of letters and numbers. Use that instead of WEP. (192.168.2.1 in the address to get into settings for router, default password is blank)

your gonna need the belkin router amplifier for that if its too far away from the router its gonna loose signal and cause you to intermittinly loose signal and connection ./... you could also contact belkin support at www.belkin.com/support

This sounds like it is probably the networking cables as your PC is directly connected so shouldnt have problems with net access. Get new cables as a first step :0)