I have a computer that the internet only work only 5 minutes after i turned it on but the computer is telling me that is connected. After these 5 minutes i can not open any web pages and anything that need connection.
If you're using a wireless connection, it is possible you are the victim of a network intruder stealing (or just hogging) your wireless internet. If this is the case, anti-virus or spyware removal software will not ultimately fix your problem, unfortunately.
If you want to find out if someone is stealing your internet, or if you just don't know, I would like to suggest you try a free wireless network security scan tool, found here: http://www.purenetworks.com/securityscan
This will diagnose any issues you may be having, and if it is a intruder, you can permanently block them from accessing your internet.
For full disclosure -- I do work for Pure Networks, so if you have any further questions, or if your problem is not caused by a network intruder, I'll be glad to help further assist you. Just ask!
the problems could come from router's prevention system because your computer be able to have virus , they sent out alot of data over network and router auto shutoff network to protect by itself, try to reinstall OS and next check router.