Webinterface is supported from 12.1(12c)EW. I suggest that you upgrade to 12.1(19)EW. To enable embedded CiscoView on SUP III/IV for Cat4000/4500 running IOS:
1. Download the additional tar file (e.g. Cat4000IOS.v4-0.tar) containing
the embedded CiscoView from the link below and put it on a TFTP server.
http://www.cisco.com/cgi-bin/tablebuild.pl/cview-cat4000
2. Download the tar file and extract the components into the flash device
chosen using the following command
Switch#archive tar /xtract tftp:/// bootflash:cv
(Note: the 'cv' after the flash device name IS REQUIRED for IOS to
recognize that files associated with embedded CiscoView are present)
3. Configure SNMP RO and RW community strings. The default is public for
RO and private for RW. This has to match what is typed in when the
web-based GUI is coming up.
Switch(config)#snmp-server community public ro
Switch(config)#snmp-server community private rw
4. Enable IP HTTP Server on the switch
Switch(config)#ip http server
5. Verify that the embedded CiscoView is properly initialized by the IOS
using the following 2 commands. If IOS does not recognize that the
embedded CiscoView is installed, you will see NO OUTPUT.
Switch#show ciscoview package
Switch#show ciscoview version
6. Open the browser from you PC and type in the IP address of the switch in
the URL. To access the web-based GUI, click on the link "Cisco View
Device Manager" and a window will pop up loading the java content.
Like for any Catalyst platform, you will need to have java-plugin
installed on your PC as well. Check the readme file associated with the
tar image for more detail on the requirement.