My computer is infected by a lot of computer threats, it tells me to call a technical helpline 1-855-746-0220. I don't know it is trustworthy. Who can give me any advice?
Popups by 1-855-746-0220 are caused by an adware. It is a technical helpline. However, never trust it, or it will ask you download and install a antivirus program which will be dangerous to your PC, since it may bundled with other unwanted program.
Keep in mind that legal program won't get into your PC without your approval and ask you to download and install unwanted programs. 1-855-746-0220 pop-ups are caused by an adware which usually gets into your PC with the help of free downloads shared on the Internet. What's more, it can hides in junk email attachments or malicious pop-up ads or links.