All of the PCs in our company are on XP with SP3 and all Windows updates installed. We have an application call 'Lawson Smart Office' which is developed by Lawson using Dot Net technology.When we run this application, we are getting frequent "Failed to execute" error on almost all PCs. In the log file we can see the following error being logged:System.IO.IOException: Unable to read data from the transport connection: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.. ---> System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. at System.Net.UnsafeNclNativeMethods.OSSOCK.recv(IntPtr socketHandle, Byte* pinnedBuffer, Int32 len, SocketFlags socketFlags) at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, SocketError& errorCode) at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags) at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size) --- End of inner exception stack trace --- at System.Net.ConnectStream.Read(Byte[] buffer, Int32 offset, Int32 size) at MForms.Runtime.XMLHTTPRuntime.Read(HttpWebResponse response) at MForms.Runtime.XMLHTTPRuntime.ExecuteRequest(StringBuilder postData) at MForms.Runtime.XMLHTTPRuntime.Execute(Request request) at MForms.InstanceController.ExecuteStart(Request request)We have worked with Lawson for a long time on this error, they said this error was from Dot Net Framework, which is out of their control.I have tested to run the same application on 3 different servers with Windows Server 2003, none of them has this error. I have also tried to run this application from one PC with Vista and there is no error on that PC as well. Therefore this error looks like only happens on PCs with XP.On my own PC I used to get this error every day, but for some reason I have not got any in the past several weeks. I have not changed any installation or configuration on my PC other than the normal Windows updates.On all other PCs with XP in our company, we still have this problem. We tried very hard to compare the Windows updates on my PC to the Windows updates on other PCs, but cannot see any major difference.Our company has to stay with XP at least for several years due to the large number of old applications only work on XP.Anyone has any insight on how to resolve this error is greatly appreciated.Thanks1 person needs an answerI do too