Hi, I have laptop. About 1 year ago I added aditional 4 gb of ram and used some time, but my laptop freezes few times, so i take it off. Also I try add 1 gb ram from my friends laptop. No isues were found, performance increased, so I use it until now. All rams are tested with memtest, latency, voltage, brand and etc. is same, but problem Its from diferent laptops and parties. My laptop started bsod, I think my hdd is dying. So I wanna ask that incompatible ram can cause system and components damage? Sorry for english...