When it was hard wired it WAS which was visible on the network......but while trying to connect it wirelessly it says that No access with having any access point.

Presumptuous that the encryption and MAC Address filtering are been disabled on the router and the driver or adapter is also defective. Also make sure that you are having the latest driver installed in the router/modem from Linksys's web site. If you are having the latest drivers already installed then make use of Device Manager for uninstalling the adapter; reboot and let Windows locate the adapter and reinstall it automatically. Your XP is at service pack 2 or 3 level, right?

Ok...if I disable the encryption....then it will have to stay that way only?? The adapter which was the brand new and it also seems to be working right with it.... I’m also having WPA as a substitute for WEP....can this is the problem?? I do have the latest driver, and I have SP2...Where do I disable the encryption?? I’m also not able to locate anywhere to disable the encryption.

WPA-PSK must also be working fine (better than WEP) with XP SP2. Encryption may be in your routers in the wireless section, and also may be labeled "security" as an alternative of "encryption."