Introduction
The Cisco Aironet CB21AG and PI21AG client adapter software is incompatible with other Cisco Aironet client adapter software
Resolution
To resolve this issue, the Aironet Desktop Utility (ADU) must be used with CB21AG and PI21AG cards. Cisco Aironet CB21AG and PI21AG client adapter software is incompatible with other Cisco Aironet client adapter software. The Aironet Desktop Utility (ADU) must be used with CB21AG and PI21AG cards, and the Aironet Client Utility (ACU) must be used with all other Cisco Aironet client adapters.
Problem Type
Software issues
Products
WLAN adapters (wireless card) / ACU (Aironet Client Utility)
Reference