Could you please give more details
Are you on a wifi connection or with an ethernet cable?
What is your supplier < orange or .....?
It mostly depends on a lot of things.
Now you could try this, by going to control panel -> system -> hardware -> device manager. Find your wireless card (network card) and click the right mouse button and choose properties.
in the "advanced" tab, depending on the type of card, there is a list of properties. If you choose "wireless mode" and uncheck the default to choose 802.11b & 802.11g .
It is especially necessary to configure a Wifi connection, which is sometimes ignored by Internet users.
If you are connected by Ethernet cable to your modem (directly), call your supplier who can test your line and guide you on the solution to take.
I wish you a better connection in the future.
Good room and good games, catsgirls.