How to Fix Slow Windows 11 Startup and Boot Time

“Slow startup” describes two different problems that happen to occur in sequence, and they have almost nothing in common. Fixing the wrong one wastes an evening.

Time them separately, once, before changing anything:

1. Power button → login screen. This is boot — firmware, drivers, services.
2. Login → usable desktop. This is startup apps launching.

On most machines the second is several times longer than the first, and it is also the easier one to fix.

If the slow part is after login

This is the common case, and Task Manager handles it directly.

Press Ctrl+Shift+Esc → Startup apps tab. You get every program that launches at login, whether it is enabled, and a Startup impact rating that Windows calculates from actual measured CPU and disk use.

Sort by Startup impact and work down the High entries.

The reliable offenders, in rough order of how much they cost:

Disabling an entry does not uninstall the program or stop it working. It just stops it launching before you asked for it.

Two worth thinking about rather than disabling reflexively: your antivirus (leave it) and OneDrive if your Desktop and Documents folders are redirected into it (disabling delays sync, it does not break anything).

The entries Task Manager does not show

Some programs start via Task Scheduler rather than the startup list, so they are invisible on that tab. Open Task Scheduler (Win+R → taskschd.msc) and look at Task Scheduler Library for tasks with an At log on trigger. Update services for third-party software are the usual finds.

If the slow part is before the login screen

This half is firmware, drivers and services. Four things account for nearly all of it.

Check that Fast Startup is on

Fast Startup saves the kernel session to a file at shutdown and reloads it at boot, skipping a meaningful portion of initialisation. It is on by default and occasionally gets turned off.

Control Panel → Hardware and Sound → Power Options → Choose what the power buttons do → Change settings that are currently unavailable → tick Turn on fast startup.

Two caveats worth knowing. Fast Startup means shutdown is not a true shutdown, so Restart is what you need when troubleshooting or installing hardware. And if you dual-boot Linux, leave it off — it locks the filesystem.

Look at the disk

Boot is thousands of small random reads, which is the worst case for a mechanical drive. Open Task Manager → Performance → Disk and check whether it says SSD or HDD.

If it says HDD, that is your answer and no amount of software tuning will meaningfully change it. An SSD is the single largest improvement available to that machine.

Also check free space — Settings → System → Storage. A system drive above 85% full slows everything including boot, because Windows needs room for paging and staging.

Delayed services

A service that fails or times out during boot holds everything behind it. Open Event Viewer (eventvwr) → Windows Logs → System, filter for Error and Warning, and look at the entries timestamped during boot.

Two common finds: a network drive that is not reachable (mapped drives block while they time out), and a service belonging to uninstalled software that is still registered.

You can also enable boot logging for detail: Win+R → msconfig → Boot tab → tick Boot log, restart, then read C:\Windows\ntbtlog.txt.

Firmware settings

Enter your BIOS/UEFI at power-on (usually Del, F2 or F12) and check:

• Fast Boot — enable it. Skips some hardware initialisation.
• Boot order — put the Windows drive first. If the firmware checks a network adapter or an empty optical drive first, each one costs seconds.
• Memory training — some systems retrain RAM every boot; there is often a setting to cache the result.

Measure what you actually changed

Event Viewer records real boot timings, which beats guessing.

Open Event Viewer → Applications and Services Logs → Microsoft → Windows → Diagnostics-Performance → Operational. Filter for Event ID 100.

Each entry shows Boot Duration in milliseconds, broken into phases. Events 101 through 110 identify specific applications and services that degraded that particular boot, by name.

Compare a before and after entry rather than trusting your impression — startup feels faster after you have just spent an hour working on it regardless of whether it is.

Clean-boot to isolate a stubborn case

If the cause is not obvious, a clean boot bisects it quickly.

1. Win+R → msconfig → Services tab.
2. Tick Hide all Microsoft services, then Disable all.
3. Startup tab → Open Task Manager → disable everything.
4. Restart.

If boot is now fast, re-enable in halves until it slows again. Remember to restore everything when you are done.

What does not help

• Registry cleaners and “boot optimisers”. No measurable effect on boot time, real risk to installed software.
• Disabling essential Windows services based on a list found online. Several popular lists break Windows Update, networking or printing.
• Defragmenting an SSD. Pointless; Windows runs TRIM on a schedule.
• Increasing the boot timeout in msconfig. That is the dual-boot menu timer, not boot speed.
• Disabling the page file to speed boot. Causes out-of-memory crashes later.

Realistic expectations

Disabling six or eight High-impact startup apps typically takes login-to-usable from a minute down to fifteen or twenty seconds, and it is the highest-return change available on most machines.

Boot itself — power button to login — is largely determined by your drive. On an SSD it is already close to as fast as it will get; on a hard drive it will stay slow until the drive changes.

If the machine is also slow once it is running, that is a separate problem: why Windows 11 is slow covers the version-specific causes, and finding what’s using 100% CPU or disk covers reading the tools.