A-Squared Free 4 is one of the better free malware removers, but it's not flawless and some users question its efficacy.
The program starts off with a sluggish detection file update that also requires a program restart. This took about 10 minutes. Normally, though, it opens to the Security Status page. From there, you can run scans, update the program, access the A-Squared knowledge base, and choose from among 20 display languages. Program options are arranged on the left nav, and they are Security Status, Scan PC, Quarantine, Logs, and Configuration tabs. Scan PC contains four scanning options: Quick, Smart, Deep, and Custom. Quick Scan is the fastest and most superficial, while the Deep Scan can take several hours.
If you choose a scan that examines your cookies, the app will recommend closing your Web browser. Custom not only lets you choose which folders to scan, but also lets you opt out of heuristic, tracking-cookie, and spyware-remnant scans. There is also a whitelist, from where you can add folders or files, which is accessible at the bottom of the main Scan tab panel. The Quarantine tab uses a spreadsheet-style layout to manage isolated files, and the Configuration tab has options for Context menu scans, Update behavior, and Permissions settings. The Quarantine tab has a neat option to rescan quarantined objects after a definition file update.
There's one annoying design quirk: important options like the whitelist are placed in the bottom left of the active panel, making them accessible only by a text link. For a standalone antimalware program that lacks a built-in scheduler and antivirus features, A-Squared Free 4 is a secure choice.