It is important to know where exactly will your role be deployed on the production machine in Azure data center. It is also important to know where windows is installed so you can reference its tools when writing startup tasks.
Well on windows Azure windows is deployed on drive D: !!!
Your role will be deployed to drive E: (E:\sitesroot\ for web role and a mirror in e:\AppsRoot for all roles)
you can learn about the location of your web role by simply open IIS Manager and explore to the web site of your role.