Open Task Manager and check CPU, Memory, Disk, and GPU usage
Run a benchmark tool such as Geekbench, Cinebench, or PassMark
Check boot time by timing how long the laptop takes to start
Test app launch speed by opening common programs and timing them
Check storage speed with a disk benchmark tool like CrystalDiskMark
Monitor temperature and throttling with tools like HWMonitor or Core Temp
Compare performance while plugged in and on battery
Check available RAM and storage space in system settings
Run a browser speed test by loading multiple tabs and websites
Use built-in diagnostics from the laptop manufacturer if available