InspectorD, I've moved your post to the Accounts and Passwords forum.
The error message that you're getting should only occur when you've become idle on your account for more than 24 hours. When this happens, Hotmail will automatically sign you out security reasons. This is called session expiration.
But, if you're getting the error message within the specified time period, it's possible that your browser is configured to block cookies from Hotmail or there is a security software in your computer that is blocking cookies from being created on your browser.
To resolve this issue, I suggest that you configure your browser to accept cookies. Here are the steps for Internet Explorer browsers:
1. Launch Internet Explorer.
2. On the "Tools" menu, click "Internet Options."
3. On the "Privacy" tab, click "Advanced."
4. Click to select the "Override automatic cookie handling" check box, and then click to select the "Always allow session cookies" check box.
5. Click "OK.”
6. Still on ”Privacy” tab, click "Sites."
7. Under "Address of Web site," type hotmail.com, and then click "Allow."
8. Repeat the previous step for "passport.com", "live.com" and for "msn.com", and then click "OK."
9. Click "OK."
• If you are using a browser other than Internet Explorer, see the documentation for that browser.