IIS 6 on windows 2003 set default limit for file upload to 200KB
To increase this limit, you can follow the steps belw to edit the IIS metabase.xml file
1. Before you can edit the metabase.xml file you configure IIS to allow editing the file.
In IIS, right click the name of the server and select properties. Check "Enable Direct Metabase Edit".
2. Find the metabase.xml file located in C:\windows\sytem32\inetserv and open the file in Notepad.
3. Search for AspMaxRequestEntityAllowed and increase the value.
The default value is 204800 (200KB). Setting the value to 5242880 will allow 5 MB file upload.
4. Go back IIS Manager to uncheck "Enable Direct Metabase Edit", and restart IIS service.
Alternatively you can run command via IIS admin utilities
Open a command prompt window and enter the following command
cd C:\inetpub\adminscripts
cscript adsutil.vbs set w3svc/ASPMaxRequestEntityAllowed max-file-size
Then Restart IIS to apply the change.