when i try to access programs fro my desktop i get an error saying that an internet connection is required but as you can see i have internet-the problem is on my home computer ,windows 7 os-before this happened i had to replace my modem and replace my power supply-can anyone help

EAS, April 2011

Make sure that you don't have a virus.
Install and run a good antivirus. Do a full scan.
(suggestions: AVG Free, Avira, Microsoft Security Essentials)

Make sure you don't have some spyware.
Install and run a good anti-styware. Do a full scan.
(suggestion: Spybot Search & Destroy)

Check your firewall settings.

From the provided informations, it seems that the firewall is forbiding some applications from communicating with the internet.

Don't unlock everything!

The message may be generated when a virus or spyware tries to call home to perform some criminal actions, steal your personnal informations or request new instruction from some criminal group...

Electro, April 2011

First you need to take the advice that you have been given here in the past. Including, if none of that advice has worked, posting MUCH MORE information about the problem and EXACTLY what the error is.

T, April 2011