How to check if wireless card is faulty

Can this be done? I have a wired connected desktop. Had it connected through Linksys wireless router to laptop. A few months ago it just stopped functioning, lost IP address etc. I returned the Linksys router to Elara, they said they checked it out and it is not faulty. I started from scratch again, defaulted the settings on both routers etc

when I ipconfig/renew I get the message "no operation can be performed while it has its media disconnected. No operation can be performed on wireless network connection while it has its media disconnected".

Help would be appreciated.

Sounds more like a driver/software configuration problem. If you don't know how to set this stuff up yourself then get advice from somebody who can. I don't understand the relevance of the "wired connected desktop" in the first sentence unless it's a typo?