XML file is not write when accessing it by creating virtual directory on IIS 5/ 6.0

Question

I am working on ASP.Net 2.0 project. I have a problem is that when we accessing this application by creating virtual directory on iis 5/6.0 then XML file is not write.It show path error.But actually path is right. But when we run application then XML file make writable. Pease help me..

with regrds RShyam