Slow PC startup: the real causes and how to fix them

A slow PC startup is almost always caused by programs that launch on their own with Windows. Next come a mechanical or nearly full hard drive, and updates waiting for a real restart. These causes can be checked in a few minutes, and most can be fixed without uninstalling anything.

The desktop appears, but the computer stays unusable for several minutes: the cursor spins, windows open in slow motion. That's often where a PC starts to feel "tired". In reality, Windows is simply launching a lot of things at once.

1. Too many startup programs

Every piece of software wants to "start with Windows": messaging apps, game launchers, printer tools, update helpers, cloud storage. One by one they're light; all together they fight over the disk and memory exactly when the computer needs them most. Beyond a dozen or so, you really feel it.

2. A "fast startup" that isn't quite what it seems

With Windows fast startup, on by default, "Shut down" doesn't fully close the system: Windows goes into a partial hibernation to start faster. It works, but small glitches pile up from day to day since nothing is ever truly reset. Only "Restart" starts from a clean slate.

3. A mechanical or nearly full hard drive

Starting up is mostly reading thousands of small files. A spinning hard drive does this slowly, and a nearly full disk leaves Windows less room to work. Below 10% free space, everything slows down, start-up included.

4. Pending updates

An update that's installed but not yet finalised can resume its work at every start-up, until the computer is really restarted. Start-up then feels slow, day after day.

1. Open Task Manager (Ctrl + Shift + Esc), then the "Startup apps" tab ("Startup" on Windows 10).
2. The "Startup impact" column rates each program from "Low" to "High". Start with the high-impact ones you don't use every day.
3. Right-click, then "Disable". The program stays installed and works normally when you open it yourself: it just no longer launches on its own.
4. Restart ("Restart", not "Shut down") and compare.

To measure precisely, Windows records the duration of each start-up in Event Viewer: "Applications and Services Logs > Microsoft > Windows > Diagnostics-Performance > Operational", event 100.

• Your antivirus, including Microsoft Defender.
• Manufacturer drivers and utilities for the keyboard, touchpad or sound, if you don't know what they do.
• Programs you genuinely need right after switching on (a work messaging app, for example).

When in doubt, disable one program at a time: it can be undone in one click in the same list.

Nyctale counts the programs launched at startup, checks whether the computer was really restarted recently or only "shut down" with fast startup, and checks the free space and health of the drive. It tells you which of these is slowing down your startup, and opens the right list so you can act.