Many viruses and malware disguise themselves as Windows processes to avoid detection, which doesn't always work. If your PC shows two explorer.exe, then chances are that one of them is a virus. I'll advise you to run a full antivirus scan on your PC as soon as possible.
If you use Windows Defender as your default AV, I'll recommend downloading a copy of the free version of Malwarebytes and performing a full system scan.