Presently using Beam Telecom internet connection (fibre optics cable), planning to purchase a modem to share internet connection. First of all, is it possible to connect the cable to modem and then share the internet connection among mobile phones, a PC, and a laptop. If so, what other equipment do I need and what steps do I need to take in achieving this. If it is possible, please suggest a modem under 1500 rupees?

Yes, It is possible but the Beam ISP people cannot give you the fibre optic cable in the phone line and just they provide you the direct no phone connection or anything and plugin and use.

If you want to share the internet connection among mobile phones, a PC, and a laptop you need to buy the router not the modem, modem is for phone line internet connection. So buy the Wifi router it's better for you and can share the Internet with all devices.

One more thing is if you want the Internet connection with spreading in high area take the high frequency router which clocked at about 5 ghz so these routers can cover more area.

If you are new to use the Wifi router, just follow the router configuration instructions that provided in the router manual. and purchase the routers like netgear, dlink, belkin, asus...etc

Just all of a sudden my computer disconnected from the router, and whenever it tried to reconnect it would just have limited access and would not have any internet access. I tried restoring my computer and nothing really happened. Right now I can connect to other internet connections fine, but when I try to join my regular router it just keeps connecting for a second then disconnects itself and keeps connecting and never works. I'm not sure if its the router's problem, as both my other computer and my phone can connect fine to the internet on my regular router

Once check with the router settings because if your ISP is providing any dynamic IP or DNS assigned IP address the router automatically detects and assigns the certain IP to the connected devices and once check with the router before connections.

If the ISP providing the static IP address you need to enter the IP address, DNS, and gateway in the router settings it should be configured then only it allows the Internet to the connected devices.

One more option is that where the router has some qos services like where you can specify mac address you need to connect to Internet and check whether QOS is disabled or not. It disconnecting automatically which means the problem is associated with the router and hard reset the router, to configure the router follow the router manual.

May be your system is infected with the virus and clean the whole system with any security programme or the network drivers are not functioning properly

Recently at school, whenever I try to connect to the internet it is extremely slow. I am on the same network as forty other students, but my connection seems to be the only slow one. Any ideas as to why this is happening?

As you are saying that forty students are connected to same WIFI this means that net will be slow obviously, because it depends on the speed. Assume that you school has 10 Mbps bandwidth and forty students are connected to it, in that 30 of them are watching you tube video and other ten students wont get the internet or the browsing will be slow.

Check your school bandwidth limit first, there are so many features in the Router to limit router. Managed Routers and Unmanaged Routers, Managed Routers have power to limited the speed to certain IP address or to certain MAC address.

check the internet speed , when you all forty students connected to same network on speedtest.net, you will come to know what exactly happening? when you are single in the class room and only you are connected to the internet once check the internet speed, you will come to know that how much speed the management is providing.

There are many reasons for this problem, May be your Laptop is infected with virus or any ongoing download is going on in background like torrents and any windows updates...etc. If you are aware of them check thoroughly. Scan your whole PC with a good Internet Security software's.

If you are downloading alot or browsing alot when connected to Internet, if this is observed by your school management they might be limiting the speed of Internet to your particular IP address or MAC address. If this is done by the management you can change the IP address, if speed limited by MAC address that is not possible to change.