If you can identify an infection, there will be some information on the web as to how you can clean it. If you do not want to bother with research, I suggest you use a couple of the free cleaning programs below. Tthey do not need any installation. Keep them on a USB and run them from there. Some people also like Malwarebytes, but Microsft Safety Cleaner and ESET Online Scanner are just as good.

Microsoft Safety Cleaner - (MSERT) Good for everyday common malware. Download a new version every week.
ESET Online Scanner - Good for hard-to detect malware. Takes a long time to run but it is worth it.
Kaspersky TDSS Cleaner - Rootkit cleaner. Detects the most common/dangerous rootkits. Does not detect all rootkits.
Dr. Web CureIT - This will find just about any malware, but there is a new version every day or so. It's too much trouble--get it only as a last resort.

Regards.