Windows server 2003 with IIS 6.0 does not support asp by default and you have to change something from the IIS manager.
1. Allow ASP web services extension
Go to Application Server management -> IIS manager ->your server -> web service extensions
Choose Active Service Pages on the right lists and ALLOW it.
2. Enable parent path on your web site setting
Go to Application Server management -> IIS manager ->your server ->
Right click on your website and choose properties -> home directory -> configuration -> options -> tick "Enable parent paths and save the setting.
3. Give the Write/revise right of your website folder to IUSER_yourcomputername account
Use windows explorer to locate the folder where storing your website files
Right click and choose properties -> Security -> Add new user name and choose this account "IUESR_yourcomputername" -> give it write,modify permission and save the settings
You may also like to check if the "Read only" property has been ticked for that folder, if it has, please untick it and save the setting.