Repair Windows

Fixing Bluescreens

The famous "Blue Screen of Death" (BSOD) is Windows' emergency brake: when the system detects a critical error, it shuts everything down before damage occurs. Sounds bad – but it's usually fixable.

Initial Diagnosis: What Does the Bluescreen Say?

Modern bluescreens display an error message (e.g., "IRQL_NOT_LESS_OR_EQUAL", "MEMORY_MANAGEMENT", "SYSTEM_THREAD_EXCEPTION_NOT_HANDLED"). This message is invaluable – Google the message with "Windows" and you'll usually find concrete solutions.

Common Bluescreen Causes

Systematic Bluescreen Diagnosis

1. Note the error message The stop code (e.g., "IRQL_NOT_LESS_OR_EQUAL") is your guide to the cause.
2. Is it reproducible? Does the bluescreen always occur during the same action? Then the cause can be narrowed down more precisely.
3. When did it start? After an update? After a software installation? After a hardware change? This is called "correlation" and is usually the cause.
4. Test in Safe Mode In safe mode, Windows starts with only basic drivers. Do bluescreens still occur here? Then it's hardware or Windows kernel. If not, it's a driver or program.
5. Update or Roll Back Drivers If a driver is suspected: install current drivers or roll back the last one via Device Manager.
6. Hardware Tests If software causes are ruled out: RAM test (memtest86), hard drive test (S.M.A.R.T.), temperature check.

Solving Driver Problems

Drivers are the mediators between Windows and hardware. If they are outdated or corrupt, devices won't work, programs will crash, or Windows will show strange errors.

Symptoms of a Driver Problem

• Device not working — e.g., printer, scanner, USB stick not recognized
• Bluescreens when connecting devices
• Audio not working or distorted
• Screen flickering or showing wrong resolution
• Bluetooth/WLAN disconnects
• Yellow exclamation mark in Device Manager

Device Manager – the Central Hub

Windows Key + X → Device Manager. Here you can see all installed devices and their status:

• Yellow exclamation mark — Driver problem
• Red arrow pointing down — Device disabled
• Question mark — Driver completely missing

Standard Procedure for Driver Problems

1. Update Driver In Device Manager: Right-click on the device → Update driver → Search automatically for drivers.
2. If that doesn't help: Reinstall Driver Right-click → Uninstall device (do not delete driver software). Then restart – Windows usually reinstalls the driver.
3. Driver Rollback If the problem occurred after a driver update: Right-click → Properties → "Driver" tab → "Roll Back Driver".
4. Current Driver from Manufacturer If Windows Update doesn't have the driver: get it directly from the manufacturer's website (NVIDIA, AMD, Intel, Realtek, etc.).

Repairing Windows

If Windows is no longer running properly – slow, unstable, endless errors – there's a repair escalation ladder: from minor intervention to reinstallation. Always work from top to bottom.

Level 1: System File Repair (sfc and DISM)

Windows has built-in tools that find and repair corrupted system files. Open Command Prompt as administrator, then:

1. SFC Scan sfc /scannow — checks and repairs corrupted system files. Takes 10–20 minutes.
2. DISM Repair DISM /Online /Cleanup-Image /RestoreHealth — if SFC finds nothing but problems persist. Takes a similar amount of time.
3. SFC Again After DISM, run sfc /scannow again — corrupted files should now be repaired.

Level 2: Restore Point

Windows automatically creates restore points before significant changes. If the problem started recently, you can revert to a previous state – without data loss.

Search "restore point" → "Open System Restore" → select a point before the problem occurred.

Level 3: Uninstall Updates

If problems arose after an update: Settings → Update & Security → Update history → Uninstall updates.

Level 4: Reset Windows

Settings → System → Recovery → "Reset this PC". You can choose:

• Keep my files — Windows will be reinstalled, your files will remain (programs will be removed)
• Remove everything — complete reinstallation, everything gone

Step 5: Complete Reinstallation

Last resort: Reinstall Windows from a USB stick. Especially for massive corruptions or if you want to sell the PC.

Keep the Registry Clean

The Windows Registry is the central database for all settings – Windows system, programs, hardware. Over the years, remnants of uninstalled programs, incorrect entries, and junk accumulate there.

Myth & Reality: Registry Cleaners

Let's be honest: Registry cleaners don't make your PC measurably faster. The Registry is so large and well-indexed today that a few thousand dead entries won't make a noticeable performance difference.

BUT: They can improve stability. If registry entries remain after uninstallation, pointing to non-existent paths, this can confuse programs – sometimes resulting in bluescreens.

When is Registry Cleaning Worth It?

• After many software uninstallations — often leaves junk behind
• After malware removal — malware leaves registry traces
• With strange error messages — missing DLL references, etc.
• After driver removal — clean up old driver configurations

How to Safely Clean the Registry?

• NEVER delete manually if you don't know exactly what you're doing. Incorrectly deleted entries can destroy Windows.
• BEFORE any cleaning, create a backup of the Registry — good tools do this automatically.
• Use conservative tools that only remove obvious junk, not everything they deem superfluous.