IIS6.0 prevent the upload of files more than +200Kb.
The AspMaxRequestEntityAllowed property specifies the maximum number of bytes allowed in the entity body of an ASP request. If a Content-Length header is present and specifies an amount of data greater than the value of AspMaxRequestEntityAllowed, IIS returns a 403 error response. This property is related in function to MaxRequestEntityAllowed, but is specific to ASP request. Whereas you might set the MaxRequestEntityAllowed property to 1 MB at the general World Wide Web Publishing Service (WWW Service) level, you may choose to set AspMaxRequestEntityAllowed to a lower value, if you know that your specific ASP applications handle a smaller amount of data.
Open your MetaBase.XML which is located in c:\Windows\System32\Inetsrv find the line "AspMaxRequestEntityAllowed" and change it to a larger number.
This change does not require stopping IIS, but to make the Metabase.xml file write-able, you need to go to the IIS control panel, right click the server, select properties, and check off the box that says "allow changes to MetaBase configuration while IIS is running".