Unauthorized Access to txt file by .Net or COM

Hello.

I'm trying to write to text file from WCF application, using stream writer and text writer.
I have 2 consumers to the WCF: console application and classic ASP.
Using WCF from console app - the txt file is created and all OK.
Using WCF from classic ASP - I get:
"System.UnauthorizedAccessException: Access to the path 'c:\AAA.txt' is denied."
Why is this?

Thanks.