Try to see if you are using any app which would effect the network by limiting it or killing it.
Best way to check it is either go to program and features section of control panel and look for any kind of program there that may effect your network.
2nd option is to open task manager (Right click your taskbar and open task manager) and see the running processes and if there is any that looks like it may effect your network like "nlimiter" "network killer" etc , then close it and uninstall it.
Sometimes Apps like these come installed with your OEM. so you need to manually delete them.
