Internet speeds can be controlled at the router level or the computer level. While you can limit speed by itself, you can also use tools to assign different settings for individual programs and set limitations for how much bandwidth they use and how they're prioritized. Built-in parental controls can also set different limits per account on a single computer and provide additional settings for blocking websites, limiting downloads and choosing which programs are acceptable to use.
Install Traffic-Shaping Software
Select, download and install a traffic-shaping program like NetBalancer, Traffic Shaper XP or NetLimiter to the computer for which you want to limit speed or bandwidth (see Resources).
Limit download and upload speeds to your computer overall, or prioritize which applications use available bandwidth first and how much they use. With some shaping programs you can set download and upload limits for specific programs.
Save your changes and modify as necessary. You may have the best results by testing your program during peak traffic hours when any differences will be most noticeable.
Modify Router QoS Settings
Access your router's control panel via a Web browser on any computer connected to the router. This is generally accessed by typing in your router's IP address, which can be found either on the router itself or in its instruction manual.
Open the QoS (Quality of Service) settings if your router has them available. The primary settings to modify are the Uplink and Downlink fields. After enabling QoS, lower the numbers in these fields until QoS takes effect.
Save your changes, then test your connection. You may need to modify the fields a few times to achieve the effect you desire.
Use Parental Controls
Open "Family Safety," then select the user account you want to limit. If you have not enabled Family Safety for this particular account yet, do so by opening and editing their account settings.
Open the options for "Web filtering," "Time limits" and "App restrictions." While you cannot control speed specifically, you can control what apps can be used, what can be downloaded and how much time the user can spend online.
Save the user's settings and apply to other users as necessary.
When using parental controls, you can make sure no one experiences bandwidth shortage by staggering the times users are allowed to be online throughout the day. This way each user gets to use your connection's bandwidth unimpeded by other users.
Not all routers will have QoS settings you can modify. If yours does not, you may be able to install third party firmware that performs similar functions.
Before changing any of your router's settings, be sure to make note of what the current settings are in case you need to revert them.
Installing firmware to your router could break it or render it unusable, so be very careful.