Increase the bandwidth of your internet. haha There is no other way. The speed comes from the provider, is the speed provided by the modem.
<sarcasm> buy an Intel-Pentium-CPU </sarcasm> *Remembers the Pentium-addvertisments from Intel for dummies*
if you are facing low speed than the promised speed from isp, call isp. if they are giving correct speed then your pc may be the problem. update to latest network driver, use tcp_optimizer tool to set best values for your internet and restart pc. you can also use winaso or other tools to fine tune speed of internet. and also use ccleaner like free tool to clean cache of internet regularly.