Overheating and loud fan noise (Even when idle)

You can separate your three suspects with two readings. Grab HWiNFO64, run it in sensors-only mode, let the machine sit idle for five minutes, and look at CPU package temperature and CPU package power together.

Temp high AND package power high (say >20 W): Task Manager only reports process CPU time — a misbehaving driver burns cycles as kernel/DPC time and keeps the package out of its deep sleep states while the process list looks clean. Check the "System interrupts" entry, and run powercfg /energy from an elevated prompt — the report names drivers and devices blocking low-power states.

Temp high but package power low (single digits): the CPU is idle and the heat simply isn't leaving. Probably the cooling path — dried thermal paste, a heatsink that's lost contact, a dust mat between the fins and the fan... The loud fans tell you nothing here; the fan is downstream of the failure, responding correctly to a real temperature.

Temp low but fans at max anyway: the CPU isn't what's driving the fan curve. Scroll through the full HWiNFO sensor list. On many boards the chassis fans key off VRM, chipset, or NVMe temperatures, and an NVMe drive sitting at 75–80 °C will peg the fans while every CPU reading looks fine. If every sensor reads cool and the fans still run flat out, it's the embedded controller misbehaving: update the BIOS/EC firmware.