when the computer overheats it will beep repeatedly when a big program is run (also when watching movies or
scrolling online), applying thermo paste will reduce the heat and fix this.

the paste costs about 3$, it is a very small syringe

put the paste on the middle of the cpu, below the heat sink (which is below the heatsink fan aka cpu fan)
then return the heat sink over the cpu, and the cpu fan on the heat sink.