Why can't I access AKO or mail.mil using my Lenovo?

What browser and OS are you using?

Chrome and Explorer work best for me - although both are inconsistent. Have you gone to militarycac.us and walked through the appropriate steps for your system?

I finally figured out how to make it work with Windows 7 and whatever IE was out then... and then Windows 8 and the respective IE came out... and just when I had it figured out, here comes windows 10 and edge.. sigh..

Try clearing out cookies and your browser data on both chrome and net explorer.
When logging into ako, use your normal certificate.
When logging into your mil mail, choose more choices when selecting a certificate, use your email certificate and press ok then input your pin.

Hope that helps.

CPT (Join to see) Lenovo's have a history of spyware and may still be restricted from use for government purposes. You might want to check with your S-6/G-6 for full details on the current situation. This may or may not be your problem, but it is worth knowing.
http://www.breitbart.com/tech/2016/10/24/report-pentagon-warns-against-use-of-lenovo-computers-over-chinese-spyware/

CPT (Join to see)
Is it turned on? Have you created an AKO account? Additionally, mail.mil is not your account, so you will not be able to access their account.

Sounds like a generic proxy error. You may have to disable your antivirus or antimalware program because it could be blocking the webpage. Kaspersky is notorious for doing this because it believes the webpage is untrusted or unrecognized. You may also have to adjust your security settings in Internet Explorer... or even your network settings if your internet service is using a firewall that uses a specific port. Without having the computer in front of me and trying different things I really can't say for sure.

More information is needed like what is your antivirus or antimalware, which could be potentially blocking the webpage. It would also be helpful to know who is your isp or if you're using a company or school connection. If you're using a school / company network they could have a firewall setup and you'll need the port number. By default your network connections automatically detect the settings.

did i just repeat myself? I'm sorry it's a habit.

It only says "page cannot be displayed" and does not go passed the login screen.