Your CPU temperatures are higher than they used to be, or you are building or upgrading a desktop and need to apply thermal paste between the processor and cooler. This guide applies to desktop PCs with removable CPU coolers on Intel LGA and AMD AM4/AM5 systems. Laptop repasting needs model-specific disassembly.
Does This Affect You?
Thermal paste fills tiny gaps between the CPU heat spreader and the cooler base so heat transfers efficiently. Over a few years it can dry out, pump out, or lose effectiveness, especially in hot or dusty systems. Replacing it means removing the cooler, cleaning both surfaces, applying a correct amount of new compound, and mounting the cooler evenly.
Power the PC off fully, unplug it, let hot parts cool, and discharge static before touching internal components. If you remove the CPU, handle it only by the edges and avoid pins or contacts. These steps are at your own risk; use warranty support if you are not comfortable.
Remove the Cooler, Clean, and Repaste
Set aside 30 to 45 minutes and work slowly on a clean surface.
- Open the side panel and locate the CPU cooler directly over the processor.
- Unplug the cooler fan cable from the motherboard header, usually labeled CPU_FAN.
- Loosen mounting screws in a diagonal or star pattern so pressure releases evenly. If the cooler sticks, twist gently rather than prying upward.
- Lift the cooler straight off and set it down with the base facing up.
- Clean old paste from the CPU heat spreader and cooler base with a lint-free cloth or coffee filter lightly dampened with 90 percent or higher isopropyl alcohol. Repeat until both surfaces are clean.
- Apply a pea-sized dot of new paste to the center of the CPU. Most modern pastes spread under cooler pressure and do not need manual spreading unless the paste instructions say so.
- Lower the cooler straight down without sliding it around, then tighten screws in the same diagonal pattern a little at a time until snug. Do not overtighten.
- Reconnect the fan cable to CPU_FAN, close the case, and power on.
After repasting, monitor temperatures with a tool such as HWiNFO or HWMonitor and compare idle and load temperatures to your previous readings. A good repaste often drops load temperature noticeably, sometimes by 5C to 15C depending on how bad the old paste was.
If temperatures are unchanged or worse, the cooler may not be seated flat, a screw may not have caught the backplate, or too much paste may have been used. Remove the cooler, clean both surfaces again, and repeat the mount carefully.
On laptops and some compact prebuilts, thermal paste replacement can involve deeper teardown and different paste behavior around direct-die cooling. That is a separate model-specific repair, not a generic desktop cooler procedure.
Sources
- Intel – How to Apply Thermal Paste (2025)
- AMD – CPU Cooler Installation and Thermal Paste Guide (2025)
- Noctua – Thermal Compound Application Methods (2024)