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.
 
Can someone tell me how to repair or solve these  

i need more information....do you have a router hub switch?.....who is your isp? look at the lights on the modem are they changing?

Read this thread:  
 
http://answers.yahoo.com/question/ [...] 323AAUwsin
 
You can use CCleaner from http://www.ccleaner.com to clean the Internet caches

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.