I think its not hijacking process . To increase your pc speed, use the link
http://daol.aol.com/articles/pc-performance/. Here,you can get step by step process to enhance your computer speed .
Due to any one of the following reasons your internet gets slow down;
1. Local network is overloaded
2. Malware or scareware on end users computers
3. Bad connection
Use the following tips to increase your internet speed :
1. Clear cookies from your browser
2. Close unwanted background tasks when you are working with the internet .
3. Scan your internet by using standard Anti-virus software
4. Reset your modem and reconnect with the internet.After that , you can test your internet speed by using
Scanmyspeed.com to get better results .