If you want add a domain name manually from your Windows 2000 / 2003 server IIS and all setting were set properly. Please follow steps below:

Create a web anonymous user
1. Log into Server
2. Right click on "My Computer" > "Manage"
3. Expand the computer management console:
Local > Local Users and Groups > Users
4. Right Click on "User" > "New User ..."
5. Enter a user name; example: domain.com_web
6. Enter a password for domain.com_web
7. Click "Create"
8. Close this console


Assign Folder Permissions
1. Right click on your web folders > "Properties"
exp: C:\domains\domain.com\www\
2. Click on "security tab"
3. Click on "Add"
4. Select the "domain.com_web" user you have just created and "Add", click "ok"
5. Allow permissions below:
- Read & Execute
- List Folder Contents (optional)
- Read
6. Click "Apply" and "Ok"

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C) Add Virtual Directory / Domain in IIS
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1. Open IIS console
2. Right Click on "Local" (Your server name) > New > Web Site > Next
3. Enter Description = domain.com > Next
4. Enter the IP address to use for this web site
5. TCP Port = 80
6. Host Header for this site = leave blank if this is dedicated IP, otherwise enter "www.domain.com" > Next
7. Path = Your web folder path
Exp: C:\domains\domain.com\www\ (The folder which we assign domain.com_web user to)
8. Check "Allow Anonymous Access to this web site" > Next
9. "Allow the following" = "Read" & "Run Scripts" > Next
10. Finish
11. Find the domain you have just added in IIS console and right click on the domain > Properties
12. Click "Directory Security"
13. Under "Anonymous Access & Security Control" click "Edit"
14. Check "Anonymous Access" and click "Edit"
15. Anonymous User > User Name = domain.com_web (the user you have created in section A above"
16. Check "Allow IIS to control password
17. Click "Ok"
18. Under "Authenticated Access", check "Integrated Windows Authentication"
19. Click Ok,