what is the symptoms of mallware, trojan in our PC/Laptop

Alot of times you will get a blue or black screen. Sometimes your computer will also be very slow or sluggish. Sometimes your computer will not let you do anything at all.

all the response is give you explanation about that. and i just give extra information. like other said, your laptop run slower. if you run some program , it will get crash and closed automatic. but for make it sure, press alt + ctrl + delete to open task manager. see on process, if any program run but you not opened it, that mean the program or file contained virus. usually, malware disabled task manager. so if your computer has infected with malware, your task manager can't opened.

There should be signs to tell u about their existence, such as loading speed, lost of data or lost in storage space. Another important sign to look out for is the number of applications u are using. If u are only using 1, yet u see more than 1 in the task manager or when your PC is in standby mode, something fishy is going on then. It's good to scan your PC/note book on a daily basis, to filter out those trojans and malware. Malware should be easier to spot since there are pop ups.

i've been there, the programs often "not responding" and weaks,,