If portal.office.com is not loading or appears to be down, start by checking your internet connection. Clear your browser's cache and cookies, then try reloading the page or using a different browser. You can also try accessing portal.office.com from another device to rule out local issues. If the problem persists, check websites like DownDetector to see if others are experiencing similar issues. Sometimes, Microsoft services may be temporarily unavailable due to maintenance. Restart your device and ensure your system time and date are correct. If needed, contact Microsoft support for further assistance accessing portal.office.com.