.Net Framework error when a new mail is detected

.Net Framework error when a new mail is detected When I receive new mail then I receive below error.
Before 3 days I am using window 7. In it I receive mail in the correct form then I install window XP In it when I try to open any mail then I receive below error. All detail of error is given below for your understanding.
Please tell me its reason and solution. I wait for your solution.

Microsoft .NET Framework
Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.
Out of memory.
Details Continue Quit
