My laptop fan spins loudly even when I’m just browsing. Task manager shows nothing obvious eating the CPU.
How do you track down the real cause? Background indexing, dust, thermal paste, a stuck update process? What’s your diagnosis routine before concluding “it’s just old”?
A constantly-loud fan means constant heat, and finding the source takes 10 minutes: (1) open Task Manager / Activity Monitor and sort by CPU — a browser tab, an updater, or antivirus stuck at 20–30% CPU is the most common cause; (2) if CPU is genuinely idle but the fan still roars, it’s thermal: dust in the heatsink (a $5 can of compressed air fixes more laptops than any software) or dried thermal paste on machines 4+ years old; (3) check the basics — laptop on a blanket blocks intake vents, and a ‘quiet/balanced’ power profile setting is free to try. If it only started recently, an update-related background index (search indexer, cloud sync) often runs hot for a day or two and then settles.