hello all. i have a new laptop with win 7 pro installed. i go to multiple client sites during the day and always hook it up to their domain/network so i can have internet access. everything was working fine until last week everything stopped. i get a certificate error each time saying i'm not trusted. their IT guy is by himself and always overworked and told me that everything was fine on his end--but didn't really have a lot of time to look. he said it was a problem on my end. i was just curious if anyone else had ever ran across the same problem and if so, how they might have fixed it. thanks in advance.

Please temporary disable the antivirus and firewall and then check the result. If the issue persists, I suggest you download the latest network adapter driver, then remove the existed network adapter and install the new downloaded driver. If the issue still occurs, please check if your TCP/IP settings. Make sure that IP address and DNS server are obtained automatically. If the above suggestions do not help, when the issue occurs, please enter "ipconfig/all > %userprofile%\desktop\ipconfig.txt, then open the file ipconfig.txt on Desktop and copy the contents into your next post.Arthur Xie - MSFT