I have running 10 instances of My Win Application WebandImage crawler which crawl a website and download images.   

But after running  30 - 40 hours some instances have been crashed.I could not understand what is the root cause of this Crashes.I am using operating system   Windows Server 2008 r2 datacenter and Visual Studio 2010.

Error-Message--

Attempted to read or write protected memory. This is often an indication that other memory has been corrupted.

Please help!