Device Manager

Open this first when a device isn't recognized or is acting up. Shows every piece of hardware Windows knows about, flags conflicts with a yellow warning icon, and lets you update, roll back, or uninstall drivers one at a time.

Event Viewer

Windows keeps a running log of everything that crashes, fails, or behaves oddly. Open Event Viewer → Windows Logs → System or Application, filter by Error/Warning, and look at timestamps that match when the problem occurred. Cross-reference error IDs with the Event IDs tab.

Services

Every background process Windows runs is a service. Open this when an app isn't working, a feature is missing, or performance is degraded — a stopped or disabled service is often the cause. Sort by Status to find stopped services quickly.

MSConfig

Controls what loads at startup and sets boot options (Safe Mode, number of processors, debug logging). Use it to isolate startup problems — disable all non-Microsoft startup items, reboot, and see if the issue disappears.

Task Manager

First stop for a sluggish machine. Check the CPU, Memory, and Disk columns for anything pegged at high usage. Startup tab shows what slows down boot time. Performance tab shows real-time graphs for all resources.

Resource Monitor

More granular than Task Manager — shows exactly which process is hammering a specific disk file, network connection, or memory address. Use it when Task Manager shows high usage but doesn't tell you why.

System Information

Generates a complete hardware and software snapshot — BIOS version, RAM slots, installed drivers, OS details. Useful for support calls when you need exact specs without opening the machine. Export to a .nfo file to share.

Disk Management

The built-in tool for creating, deleting, resizing, and formatting partitions, and assigning drive letters. Use it when a new drive isn't showing up in File Explorer, or when you need to initialize a fresh disk.

SFC Scan

Scans all protected Windows system files and replaces corrupted or missing ones from a cached copy. Run this when Windows is behaving strangely, apps won't launch, or after a malware cleanup. Takes 5–15 minutes — requires admin and must complete fully.

DISM Restore

Repairs the Windows component store that SFC draws from when fixing files. Run DISM first, then SFC — if SFC runs against a corrupt store, it can 'fix' files with bad versions. Requires internet or installation media. Takes 10–20 minutes.

Check Disk

Scans the file system and checks for bad sectors on the drive. The /f flag fixes file system errors; /r locates bad sectors and recovers readable data. Requires a reboot to run on the system drive. Run when you suspect storage issues.

Winsock Reset

Resets the Windows network stack (Winsock) to its default state. Use when network apps fail but connectivity tests pass — often caused by VPN software, malware, or failed network driver updates. Requires a reboot to take effect.

IPConfig All

Shows the full picture of every network adapter — IP address, subnet mask, default gateway, DNS servers, MAC address, and DHCP lease info. The first command to run on any network problem. Use to confirm whether DHCP is working and what DNS the machine is using.

DNS Flush

Forces Windows to forget all cached DNS lookups. Use when a website resolves to an old or wrong IP address, or after updating DNS records. Harmless and instant — the cache rebuilds naturally with fresh lookups.

Full DNS Reset

Combines three commands: releases the DHCP lease, renews it (gets a fresh IP), and flushes the DNS cache. Use when the machine has no IP or is stuck on a stale network config. Requires admin.

Ping Test

Sends continuous pings to Google's DNS server (8.8.8.8) to test basic internet connectivity. Watch for 'Request timed out' or increasing response times — packet loss here means a network path problem. Press Ctrl+C to stop.

Tracert

Traces the route packets take to reach a destination, showing each router hop and response time. Use when ping succeeds but something specific is failing — look for the hop where timeouts start or latency spikes.