The client radio must be turned on to perform tests.
Generally Linktest is run to test the quality of the link between the adapter and the access point. Linktest will not work unless the link is established which might due to one of the following reasons
1. Wireless adapter is not turned on[Error Message indicates this] or not installed properly
2. Wireless adapter is not associated.
For more information, refer to the Troubleshooting section of Cisco Aironet Wireless LAN Client Adapters.
WLAN adapters (wireless card) / ACU (Aironet Client Utility)
Client OS Type
Link Status Meter Test Result
Client Adapter Errors, Warnings, Statistics and Log Messages
Cannot run a linktest radio in W LAN Adapter not on