ESET SysInspector is a powerful, portable security tool that will inspect your system's files, running processes, Registry keys and more, looking for and highlighting anything that could be a sign of malware.

The program works relatively quickly, using heuristics rather than signatures to identify potential threats. And so even when we ran it on a test PC with terabytes of data, SysInspector completed its scan in a fraction under 90 seconds, delivering its verdict on everything from running processes to network connections, services and drivers to Registry keys, scheduled tasks and key system files.

The usefulness of this report will vary, depending on your system. Running processes, for instance, are displayed in three colours to highlight them as safe, "unknown" or risky. And that sounded fine, until we found SysInspector flagged no less than 35 processes as "unknown" on our test PC: we could have trimmed down the list of suspects further manually.

Other sections of the report were more interesting, though, with the program quickly highlighting a suspect printer monitor, some dubious auto-start programs, a couple of questionable TCP connections and other possibly relevant details.

SysInspector can't then actually do anything with this information: it's not an antivirus tool, and isn't able to remove any malware that it might find. If you think you might be infected by something, though, it's a good way to start the detective work of trying to identify the source. Especially as it's portable, so there's no need to worry about installation: just leave the program on a USB key, and run it whenever you're worried about malware and need a second opinion.