How-to
How to add or reset your Microsoft 365 sign-in verification method (MFA)
Last Updated: October 14, 2026Add, change or replace the way you prove who you are when you sign in to Microsoft 365 (Microsoft Authenticator, phone, passkey or security key), including what to do when the old phone is lost. For admins, it covers resetting a user's methods in the Microsoft Entra admin center, the Temporary Access Pass, and how to help a locked-out user safely.
How to run a script on a schedule with Task Scheduler and PowerShell
Last Updated: October 14, 2026Set up a PowerShell script to run on a schedule on Windows 10, Windows 11 or Windows Server, either in the Task Scheduler window or with the ScheduledTasks cmdlets. Covers which account to run it as, how to see why a run failed, how to test it, and how to remove it again.
How to make a bootable Windows 11 USB installer
Last Updated: October 14, 2026Build a Windows 11 installation USB drive with Microsoft's Media Creation Tool, or by hand from the Microsoft ISO using FAT32, GPT and DISM when install.wim is over 4 GB. Includes checking the ISO hash, UEFI and Secure Boot notes, the TPM 2.0 requirement, booting from the drive and an offline build.
How to set up SSH key login and turn off password login
Last Updated: October 14, 2026Replace SSH passwords with a key pair, prove the key works from a second session, and only then switch password login off on the server. Covers Linux, macOS and Windows clients, the sshd_config.d trap where another file overrides you, and how to get back in if you lock yourself out.
How to find which program is using a port, and stop it
Last Updated: October 14, 2026A service will not start because "address already in use" or "port 80 is already in use". This article shows how to find the program that owns the port on Windows and Linux, how to tell a normal service from a stray process, and how to stop it safely.
How to flush the DNS cache and test name resolution
Last Updated: October 14, 2026A name resolves to the wrong address, or not at all, after a DNS change. This article shows how to clear the local DNS cache on Windows, macOS and Linux, how to check which server answered and what it said, and how to tell a stale cache from a broken DNS server.
How to turn on Remote Desktop safely on Windows 11
Last Updated: October 14, 2026Remote Desktop is two clicks to switch on and easy to switch on badly. This article turns it on in Windows 11 with Network Level Authentication, a short list of allowed users and a firewall rule limited to your own subnet, and explains why TCP 3389 must never face the internet.
How to find your BitLocker recovery key, and back it up before you need it
Last Updated: October 14, 2026A BitLocker recovery screen is only a bad day if nobody knows where the 48-digit key is. This article shows where Windows keeps it (Microsoft account, Microsoft Entra ID, Active Directory, a printout), how to match the right key using the Key ID, how an admin looks it up, and how to back it up from a working machine.
How to free up disk space on Windows
Last Updated: October 14, 2026The system drive is nearly full, the capacity bar is red or updates will not install. Work from the safe built-in tools (Storage Sense, Disk Cleanup, component store cleanup) towards the trade-offs (hibernation, the page file, restore points), and learn what never to delete by hand.
How to repair Windows system files with SFC and DISM
Last Updated: October 14, 2026Windows features misbehave, updates fail or apps crash because protected system files or the component store are damaged. Run DISM first and then SFC, read the CBS.log result, and fall back to an offline source or the recovery environment when the PC cannot repair itself.
Power Automate: Forms checkbox answers arrive as one run-together line
Last Updated: September 19, 2026A Microsoft Forms checkbox question lands in your Power Automate email as ["one","long","line"] instead of a list. One Compose action and one expression fix it in about ten minutes.