two iexplore processes are showing in taskmanager even when i have only one ie window opened ( Windows 7 Release Candidate build 7100).I got this behaviour suddenly one week back.I doubt this to be a virus.But i checked with all antivirus programs but none turned up for detection.

Hi, Have you installed Windows live it is the other Iexplore. It should be at the top of your IE8. Slan go foil, Paul

From what I have seen this is related to having Internet Explorer 8 installed. The first instance is the "wrapperr" and each additional instance relates to a tab being opened. The more tabs you open, the more instances of IE8 will be shown in the Task Manager. This is by design on Microsoft's part, if one tab crashes it doesn't take down all your other open tabs.

But what i see is i have only one ie window opened but some 20 iexplore processes in my task manager.I have also installed windows live essentials.

So I understand that you are saying you have only one website open.Windows Live applications don't identify themselves as iexplore.exe or as iexplore.exe*32.At this point I would suggest running a full scan of your computer using http://onecare.live.com/site/en-au/center/whatsnew.htmor you could use a seperate computer and download VipreRescue from http://live.sunbeltsoftware.com which is able to run in safe mode without a network connection. McAfee Stinger may also be a good choice to scan with, it can be retreived from http://vil.nai.com/vil/stinger/.Edited for spelling...

This post from the Internet Explorer Team Blog explains what you're seeing - http://blogs.msdn.com/ie/archive/2008/07/28/ie8-and-reliability.aspx - Jake MSFT Internet Explorer Outreach Team

Thank you Jake, excellent information.