🔎 Step 1: Find the Problem
Press Ctrl + Shift + Esc → open Task Manager → check which process uses the most CPU.
🧩 Step 2: Disable Background Services
Press Windows + R, type
services.msc.Stop or disable unnecessary services like SysMain, Windows Search, or Print Spooler (if unused).
🦠 Step 3: Scan for Malware
Open Windows Security → Virus & threat protection.
Run a Full Scan.
Malware often causes 100% CPU spikes.
⚙️ Step 4: Clean Startup Apps
Disable all non-essential apps from Task Manager → Startup Apps.