You can use services like VirusTotal to do a quick file check if you suspect anything. You can also check what services/program starts on boot (msconfig and ser

You can use services like VirusTotal to do a quick file check if you suspect anything. You can also check what services/program starts on boot (msconfig and services.msc). With that you can already have a good confidence level of not being infected without have an AV draining your computer performance.