Farbar Recovery Scan Tool, or FRST, is a portable application designed to diagnose malware issues. Also available for 32-Bit.

For scanning and live protection consider downloading Malwarebytes.

It is also possible to run FRST in the Windows Recovery Environment in order to diagnose and fix boot issues.

Farbar Recovery Scan Tool quickly scans and then displays detailed information about the Windows Registry loading points, services, driver services, Netsvcs entries, known DLLs, drives, and partition specifications. It will also list some important system files that could be patched by malware. The report provided is automatically saved as FRST.txt in the same directory as the original download for easy access. It contains a lot of information but is presented in a relatively easy to read format.