2 Answers

Tip here :http://www.sheffieldforum.co.uk/showthread.php?t=95200

Try to disable work offline in Internet Explorer on your computer and check if the issue gets fixed.
Method 1: Open Internet Explorer>Tools(in right-hand top corner)>Menu Bar>File>click on
"work offline" to untick it.
Tools>Menu Bar is if you do not already have "file, edit, view, etc".
Method 2: Open Internet Explorer>Tools>Click on "work Offline" to untick it.
Method 3: Reset Internet Explorer settings:
To determine whether a performance issue or an error message is caused by configuration settings, reset Internet Explorer to its default configuration. This was its state when Windows Vista was originally installed.
To reset Internet Explorer settings automatically, click the Fix it button or link in the below article. Click Run in the File Download dialog box, and follow the steps in the Fix it wizard.
Refer the below article which has step by step information in detail to optimize IE.
http://support.microsoft.com/default.aspx/kb/936213 

http://answers.microsoft.com/en-us/ie/forum/ie8-windows_other/my-computer-keeps-going-to-working-offline/7cc4502e-2496-488a-a213-9b34e4bcf9c1