|That's not much information to go on......|
Are you using Internet Explorer, or another browser?
What, if any, error messages do you get?
How did you conclude that the internet connection is strong?
How do you connect to the internet? e.g. Wireless Modem/Router, Cable, Dial-up, etc.
Try downloading and running this winsock repair file. Let us know if this helps, because we can then try to determine the underlying cause of the problem (usually malware).
It may be caused by having too high a security level set, or another, browser-specific setting.
Please let us know if you found someone's advice to be helpful.