Question PC randomly freezes for no reason and the monitor glitches a lot ?

full system spec? include brand and model of the psu
what the cpu temp?
how full is the storage?
malware scan the system?
bro no malware, and storage 40 percent only and cpu temp 42 on normal use. Also heatsink fan not working plus i took my pc to a Lenovo centre and they can't fix it
 
is an old aio with hdd.
check the temp?
upgrade to a ssd?
malware scan the system?
Temperature is good and also i think maybe it was ram because i noticed that my aio has one samsung and one lenovo ram stick and one of the ram even felt lose