Windows already ships with powerful repair tools — they are just hidden inside the black Command Prompt window. This guide shows the core commands technicians use daily to repair system files, fix the network and check disks, without installing a single program.
Most PC users install a "PC fixer" program for every small problem — and many of those programs do more harm than good. Professional IT admins do the opposite: they open Command Prompt and use the repair tools Microsoft already built into Windows. A single CMD window can scan and repair Windows system files, rebuild a broken network connection, check a hard disk for errors, reset a stuck Windows Update, and reveal information like saved Wi-Fi passwords and your PC's serial number. This page is your starting point: the most important command groups in the toolkit, what each one actually does, and the correct order to use them. Every command below is meant to be copied exactly as written. Most repair commands must be run in a Command Prompt opened as Administrator (right-click the Start button, choose Terminal (Admin) or Command Prompt (Admin)).
When Windows behaves strangely — apps crashing, features missing, strange error messages — the cause is often a corrupted system file. Two built-in tools handle this:
DISM /Online /Cleanup-Image /RestoreHealthsfc /scannowDISM downloads clean replacement components (it needs an internet connection), and SFC then uses them to fix damaged files. Running them in this order gives the best result.
"Wi-Fi connected but no internet" is the most common complaint in any office. Before touching the router, refresh the PC's network from CMD:
ipconfig /release — drops the current IP addressipconfig /renew — asks the router for a fresh IP addressipconfig /flushdns — clears the saved website-address cachenetsh winsock reset — resets the Windows network socket catalognetsh int ip reset — resets the TCP/IP stack, then restart the PCA slow, freezing PC or files that refuse to open can mean file-system errors or bad sectors on the disk. CHKDSK is the built-in disk doctor:
chkdsk C: /scanchkdsk C: /f (it will ask to run at the next restart — press Y)chkdsk C: /r (slower — it also tries to recover readable data)Technicians constantly need details that Windows hides deep inside Settings. CMD answers in one line:
systeminfo — full report: Windows version, install date, RAM, last boot timewmic bios get serialnumber — the laptop/PC serial number (needed for warranty and driver downloads)netsh wlan show profiles — every Wi-Fi network this PC has ever joinedipconfig /all — IP address, gateway, DNS and MAC address of every adapterThe toolkit also covers daily admin work that normally takes many clicks:
net user Ravi MyPass123 /addnet localgroup administrators Ravi /addnet stop wuauserv / net start wuauserv (this is the Windows Update service — stopping and restarting it is part of fixing stuck updates)shutdown /s /t 3600 (3600 seconds = 1 hour; cancel with shutdown /a)These are only the highlights. The full video walks through the complete toolkit — hundreds of practical commands grouped by job — with live demonstrations of what each one does on screen.
The full collection of commands, demonstrated live with real examples — this is the video this guide is based on.
▶️ Watch Full VideoYes — every command in this guide is an official Microsoft tool built into Windows. They do not delete your personal files. Just type commands exactly as written, use an Administrator Command Prompt where noted, and avoid random commands from unknown websites.
Repair and system commands need administrator rights. Close the CMD window, then open it again by right-clicking the Start button and choosing Terminal (Admin) or Command Prompt (Admin), and run the command again.
No. Command Prompt, SFC, DISM, CHKDSK, ipconfig and netsh are part of Windows 10 and Windows 11. That is the whole point of the toolkit — the repair tools are already on your PC, you only need to know the commands.