Hope this helps,
Ok, I apologize i misunderstood your original question.
If you look down by your clock do you see a picture of a little computer (this is your wireless connection) if so right click on it and click on show available wireless networks. Does it show any available networks?
Are there any other computers close by that can connect to the internet over wireless connection? So we can see if it is just your machine or if this is an issue with the wireless router?
When was the last time this was working correctly it is possibly the driver or a system file became corrupted.
Did you recently do any updates from Microsoft or add any new software on to this computer?
I am trying to narrow down what is causing this to have become disabled.
Lets try doing a system restore by following the steps below, you will not lose any files or data by doing this. It will just restore all the configuration files back to a previous state.
Click Start, point to All Programs, point to Accessories, point to System Tools, and then click System Restore.
On the Welcome screen, click Restore my computer to an earlier time, and then click Next.
On the Select a Restore Point page, select the date from the calendar that shows the point you'd like to restore to
On the Confirm Restore Point Selection page, verify that the correct restore point is chosen, and then close any open programs.
Click Next if you are ready to proceed or click Back to change the restore point.
The computer will shut down automatically and reboot. On reboot, you'll see the Restoration Complete page, and then click OK.
Now lets see if your wireless is working again.