Enabling UTF-8 Format for Non-English Languages and Security (IIS 6.0)
IIS does not support the UTF-8 format for FTP site log files.
UTF-8 is a method of character encoding that allows for both single and multibyte characters in one string. If you want to read text-based (W3C Extended, IIS, and NCSA Common) log files in a language other than English, you can enable the UTF-8 format. You also need the UTF-8 format if you serve URLs in a language other than the native server code page, for example, if you serve Chinese URLs on a Japanese system. In addition, because IIS 6.0 tries to serve URLs in code pages other than the server default code page by default, you might want to enable the UTF-8 format for security reasons. It is a good security practice to enable the UTF-8 format in case of an attack based on URLs in UTF-8 that might not translate correctly to the default code page.
Important You must be a member of the Administrators group on the local computer to perform the following procedure or procedures. As a security best practice, log on to your computer by using an account that is not in the Administrators group, and then use the runas command to run IIS Manager as an administrator. At a command prompt, type runas /user:Administrative_AccountName "mmc %systemroot%\system32\inetsrv\iis.msc".
To enable UTF-8 format