DLLimport help

[skinnyreptile]

I have two projects, one create a C++ DLL and the other one is a web application which use DLLimport to link to the C++ DLL. Both of my programs run smoothly except after I run my web application then come back to modify my DLL application. I received the following error message,

fatal error LNK1104: cannot open file 'Release/Test_CPP_DLL.dll'

I have to restart my PC in order to compile my DLL program again. I believe my web application does not release the handle of the DLL. Is there any code in C# to free a library when done?

Thank you for the help.