Resolution
In Cisco Catalyst 4000/4500 Series switches, the software running on the Supervisor(Sup) cannot be converted from CatOS to Cisco IOS , nor can the reverse action be performed.
The software supported on Cisco Catalyst 4000 Series switches depends on the hardware architecture implemented. The 4000/4500 switches with Sup1 and Sup2 run only CatOS and cannot be converted to support Cisco IOS. Similarly, the 4000/4500 switches with Sup2+, Sup3, Sup4 and Sup5 only run Cisco IOS. They cannot be converted to support CatOS.
The only way to convert a Cisco Catalyst 4000/4500 Series switch from CatOS to Cisco IOS, or from Cisco IOS to CatOS, is through an upgrade of the hardware (Supervisor Engine).
Refer to Recover a Cisco IOS Catalyst 4500/4000 Series Switch from a Corrupt or Missing Image or in Rommon Mode for more information.
