Whenever i use internet, my pc works bit slow. What will be the reason?

It looks to be a virus problem. you must purchase an antivirus as soon as possible or if you have update its database or have a free online scan of your. be careful while using pendrive or internet afterwards Abhishek Jain

Are you facing the problem very recently or it is a problem you are facing so long? Then PC can be slow down ddew to so many reason: 1. What is the size of RAM? What is the speed of your processor? 2. How much virtual memory do you set in your PC? 3. Do you clear the temporary files regularly? 4. How much free memory you have in your Operating System Drive of your PC? All the points are very important. So, in future whenever you face the problem please don't forget to inform the configuration of your PC.

It sounds to me like you may have a lot of adware and spyware on your computer. You may also have some viruses. I recommend you download a program called Super Anti-spyware (superantispyware.com), and run it on your computer every few days. It is easy to install and use, and it will work in conjunction with your current anti-virus program. The program is free to download and use, and it works really well at keeping your computer clean if you use it regularly. It is also free and easy to upgrade to keep the program up-to-date. I have a friend who owns a computer repair shop, and this is the program he recommends to his customers...