There's a couple of things that you can try.
For the disconnections it could well be your provider - have you contacted them to have your line tested ?
Disconnections can also be caused by interference from other local users when using just a Wifi connection and a channel change in the router can resolve that.
To determine if it is a Wifi problem then wire the router to the computer to see if you still get the disconnects.
To determine which channel the router is broadcasting on as well as other local users, open a command prompt and enter
netsh wlan show networks mode=bssidRight click in the command window text area and click on Select all then press enter.
You can then right click in the reply box and select Paste so I can have a look at the output and let me know your SSID (network name).
It's possible there could have been firmware upgrades for your router model, so go to the vendor's support site and see what they have for your model.
http://support.sagemcom.com/site/sagemcom_carte.phpIf they have a f/w upgrade, log into the router and look for the bit that allows you to back up the existing config. as some f/w updates can cause problems.
If you feel the router is playing up, switch the computer and router off as well as disconnecting all cables for a couple of minutes - reconnect the cables and switch just the router on until all lights are back on and then switch on the computer.
If you are using a separate modem and router, you do this for the modem as well, but just switch the modem back on and let it initialize first before switching the router back on.
This is known as a power cycle and can usually clear a number of ails.
There are also a couple of other commands that can help with connectivity/browsing and they are done from an elevated command prompt -
netsh winsock reset catalog
netsh int ip reset resetlog.txt
exitThen reboot.
Not being able to browse can also be caused by security programs blocking connectivity and to determine if this is the cause, boot up into Safe Mode with Networking and then see how it performs.