the only way to remove an infection and all the secondary effects (disabled features, random crash) for sure is to reinstall the system.
This is not true. I have some infected PCs fixed, and the only user accounts infected were those who were in use. If other user accounts with admin rights can login with no sign of malware, try to remove malware with those accounts, it's gonna save time.
First of all, malware is not exactly the same as virus All malware, who purposely destroys user's docs, system files, apps, OS and/or MB, is called virus; they normally detect and infect all user accounts, they spread by all means, such as USB key, floppy disk, HD, internet, CD, and etc., if you've got virus, you cannot realize it immediately, and in some cases you have to reinstall OS. Second type of malware tries to install backdoor software, and steals personal info Other malware (except for those mentioned above) wants to seduce people to purchase some fake antivirus/antimalware software, it requires your interaction when people gets infected from malicious websites, and they are seen right away. This type of malware normally cannot be removed by antivirus without untimalware plugin installed, you have to remove them either using untimalware such as malwarebytes or remove them manually. As of 10 - 20 users, what's your point? do you think you do not need to backup all individual docs and reconfigure all accounts, when you reinstall OS? According to my experience, malware only infects the active user account you are using, other accounts are in good health, no matter they have admin rights or not.
a little off topic,can a virus actually destroy hardware?. i.e.hard drive,memory,cpu? or just infect files in OS?
My whole pc was infected,all exe. files, i couldn´t even go to internet,so i wondered is that malware or a virus?
I couldn´t do anything,so i tried with Kaspersky rescue disk,but it didn´t show anything,no malware,spyware,trojans...so i had to format