How to compile with Bison

[tindlp00]

Hello!!!
I have been using Yacc till now, but I want to prove Bison. I have the next 
files:
        bison.exe
        bison.hairy
        bison.simple
I have bison.exe, bison.hairy and bison.simple in a directory called Area 
(c:\Area) and I have set the following enviroment variables:
Set bison_simple=c:\area
Set bison_hairy=c:\area
But when I try to compile a bison file, I receive an message like this: 
        C:\AREA\BISON.EXE:  c:\area: Permison denied
Are bison.simple and bison.hairy correctly located? If they aren´t, where do I 
have to put these files in Windows98 platform to make bison works?
Do I have to do any more change?

Thank you very much.