Greetings- I have an old Lenovo from maybe 2000. THe internal wireless card is not supported by Intel since 2003. It connects to unsecure networks, but never to a secure one. Error reads: "Searching for a valid certificate." Got a USB wireless N, and it still connects to unsecure but not secure. No error this time, it just hangs. Any thoughts? Thanks!
I know this is an older post, but recently came across this same issue, and wanted to post the fix in case someone else came across this. Just re-setup a Netgear wireless access point with 2 netgear repeaters. The configuration required me to use WEP. After setting it up, everyone else was able to get on except one laptop - a Lenovo running XP Pro. Was getting a wierd Certificate error. I knew it was bogus, so I went in and made sure the old SSID profile was gone (Control Panel - Networking - Wireless Properties - Wireless Networks Tab, then remove the SSID). Then I set it up MANUALLY. After that it worked. For some reason, trying to select it from the list of available wireless networks doesn't seem to work.