Upgrading to Windows 11 should take about an hour and leave your PC running better than before. In reality, it breaks audio, kills Wi-Fi, slows everything to a crawl, and occasionally turns a perfectly good computer into a very expensive paperweight — and Microsoft's own support pages are written by people who've never actually touched a broken machine.
Here at Campoverde Repair on the Costa Blanca, we've unpicked hundreds of botched Windows 11 upgrades since the rollout began. Below are the questions we hear most often, answered straight — no jargon, no runaround.
Why Is My PC So Slow After Upgrading to Windows 11?
Windows 11 runs background indexing, telemetry uploads, and a full OneDrive sync immediately after setup — all at the same time. Your machine isn't broken; it's just being hammered from the inside while you're trying to use it. Give it 30–60 minutes after the first reboot, then check Task Manager (Ctrl + Shift + Esc) to see what's still chewing through your CPU or disk. If the disk usage is sitting at 100% for more than an hour, SysMain (formerly Superfetch) is usually the culprit — disable it in Services and you'll feel an immediate difference.
Why Has My Wi-Fi or Ethernet Stopped Working?
Windows 11 frequently installs generic network drivers that don't play nicely with older Realtek or Intel chipsets. The fix is to go to your router manufacturer's or PC manufacturer's website, download the exact driver for your model, and install it manually — not through Windows Update. If you can't get online at all, use a USB-to-Ethernet adapter on another machine to download the driver, then transfer it via USB stick. Nine times out of ten, this resolves it within ten minutes.
Why Is There No Sound After the Windows 11 Update?
Audio is the single most common casualty of a Windows 11 upgrade. The update replaces your Realtek HD Audio driver with a "universal" Microsoft one that simply doesn't work on most laptops and mid-range desktops. Right-click the speaker icon, open Sound Settings, and confirm Windows is even seeing your output device. Then head to Device Manager, find your audio device under "Sound, video and game controllers," right-click it, and choose Update driver → Browse my computer → Let me pick — selecting the older, working driver from the list often solves it instantly without downloading anything.
Why Does My Printer Refuse to Work Now?
Printers and Windows 11 have a genuinely terrible relationship — especially anything more than three or four years old. Microsoft removed legacy printer driver support, so your HP, Canon, or Epson may not even be recognised anymore. Uninstall the printer completely from Settings → Bluetooth & devices → Printers & scanners, then go to the manufacturer's website and download a Windows 11-specific driver — not the Windows 10 one. If no Windows 11 driver exists for your model, that's planned obsolescence in action, and you're looking at either a new printer or a workaround via a third-party print server.
Why Do My Apps Keep Crashing or Freezing?
Windows 11 introduced a stricter security model and changed how certain older applications interact with system memory. If a specific app keeps crashing, right-click its shortcut, go to Properties → Compatibility, and run it in Windows 10 compatibility mode. Also check that your Visual C++ Redistributables and .NET Framework are up to date — a huge number of app crashes trace back to these components being outdated or corrupted during the upgrade. If it's happening across multiple apps, your Windows installation itself may be partially corrupted.
Can I Roll Back to Windows 10 If Things Are Too Broken?
Yes — but only within the first 10 days after upgrading. After that, Windows deletes the recovery partition automatically and rollback is no longer an option from within Windows itself. If you're still inside that 10-day window, go to Settings → System → Recovery → Go back, and follow the prompts. Miss that window, and your realistic options are either fixing Windows 11 properly or doing a clean install of Windows 10 from a USB stick — which means wiping the drive. Back up your data before you do anything.
Why Is My Screen Flickering After the Windows 11 Upgrade?
Screen flickering almost always points to a graphics driver conflict. Windows 11 is notorious for overwriting Nvidia and AMD drivers with its own stripped-down versions — which then fight with any leftover components from the original driver. Open Device Manager, right-click your display adapter, and uninstall it completely — ticking the box to delete the driver software. Reboot, then download the latest driver directly from nvidia.com or amd.com (not Windows Update). Do not let Windows automatically reinstall it; always download manually from the GPU manufacturer.
Why Is Windows 11 Saying My PC Isn't Compatible — Even Though It Upgraded?
This happens when the upgrade ran via the "PC Health Check" workaround or through a media creation tool that bypassed TPM 2.0 and Secure Boot requirements. The system upgraded fine but now shows watermark warnings or refuses certain features. You're not in immediate danger, but Microsoft could push updates that brick unsupported installs in the future. The real fix is either enabling TPM 2.0 in your BIOS (many older machines have it disabled by default, not missing) or accepting that the hardware genuinely needs replacing.
Why Is File Explorer Crashing or Running Slowly?
The new Windows 11 File Explorer uses significantly more RAM than its Windows 10 predecessor, and on machines with 4GB or less it struggles badly. First, open Task Manager and kill any rogue explorer.exe processes, then restart it fresh. If the problem persists, go to View → Options and disable "Show recently used files" and "Show frequently used folders" — these features query your drive constantly and compound the slowness. Machines with less than 8GB of RAM are going to feel this pain daily; upgrading RAM is the permanent fix.
Why Does Windows 11 Keep Installing Updates and Restarting Without Permission?
Windows 11 Home gives you almost no control over updates — Microsoft made sure of that. You can delay updates by up to five weeks via Settings → Windows Update → Advanced Options → Pause Updates, but you cannot stop them permanently on the Home edition. Setting your connection as a "Metered Connection" (Settings → Network & Internet → your Wi-Fi → Properties) prevents background downloads but isn't a guaranteed block. If you need real control over your update schedule, Windows 11 Pro is the only edition that gives it to you — and it's worth the upgrade if updates keep disrupting your work.
Still Not Sure What's Wrong With Your Machine?
The question most people overlook is the File Explorer and RAM one — because it feels like a software glitch when it's actually a hardware limitation being exposed by a more demanding OS. If your PC has 4GB of RAM and it's running slowly across the board after the upgrade, no amount of driver tweaking will fix it. The OS has simply outgrown the hardware, and no tech blog is going to tell you that as clearly as we just did.
Key Takeaways
- Post-upgrade slowness lasting more than an hour is almost always caused by SysMain or OneDrive sync — disable SysMain in Services for an immediate speed boost.
- Audio and Wi-Fi failures are driver conflicts; always download drivers manually from the manufacturer's website, never through Windows Update.
- The rollback window is only 10 days. If you're going back to Windows 10, do it now — not next week.
- Screen flickering = GPU driver conflict. Uninstall completely, reboot, and reinstall from nvidia.com or amd.com directly.
- If your machine has less than 8GB of RAM, Windows 11 is going to hurt — adding RAM is the only permanent solution, not a software workaround.
- When in doubt, bring it in. A botched upgrade takes us 1–2 hours to sort properly; it takes most people days of frustration and risk of data loss.
Frequently asked questions
How do I fix no sound after upgrading to Windows 11?
The most common cause is Windows 11 replacing your Realtek audio driver with a generic Microsoft one. Open Device Manager, find your audio device under 'Sound, video and game controllers,' right-click it, and manually select the older working driver from the list. If that doesn't work, download the correct driver directly from your PC or motherboard manufacturer's website.
Can I go back to Windows 10 after upgrading to Windows 11?
Yes, but only within the first 10 days after the upgrade — after that, Windows deletes the rollback data automatically. Go to Settings → System → Recovery → Go back to roll back. If the 10-day window has passed, you'll need to do a clean install of Windows 10 from a USB stick, which will erase your drive.
Why is my PC running so slow after the Windows 11 update?
Immediately after upgrading, Windows 11 runs background indexing, OneDrive sync, and telemetry all at once, which can max out your CPU and disk for an hour or more. If the slowness continues, disable the SysMain service in Windows Services — it's a common culprit that drains resources unnecessarily. Machines with less than 8GB of RAM will also struggle with Windows 11 long-term.
Why did my Wi-Fi stop working after the Windows 11 upgrade?
Windows 11 often installs generic network drivers that conflict with older Realtek or Intel Wi-Fi chipsets. Download the correct driver for your exact PC model directly from the manufacturer's website and install it manually, bypassing Windows Update entirely. If you can't get online, use a USB-to-Ethernet adapter or transfer the driver via USB stick from another computer.
Does Windows 11 work on older PCs?
Officially, Windows 11 requires a TPM 2.0 chip, Secure Boot support, and at least 4GB of RAM — which rules out most PCs made before 2017. Many older machines have TPM 2.0 disabled in the BIOS rather than missing, so it's worth checking before assuming your hardware is incompatible. Running Windows 11 on unsupported hardware is possible but risky, as future updates from Microsoft could block or break the installation.