As anyone who’s tried will attest, it’s not easy to remove malware manually. You confidently delete every trace of the errant program you suspect is the culprit, and then it reappears on the next reboot, ready to plague your system once more. And there’s a thought in the back of your mind, saying there has to be that one file in here somewhere that can be deleted and everything on the computer will be shipshape again. Unfortunately, it’s rarely that simple.

Luckily, there are solutions to almost any malware-related problem, provided you know what you’re facing and what to download. In most cases, all it takes is a proper estimation of your situation and an internet connection (or, in the worst of scenarios, a flash drive and the use of another computer). With that in mind, here are the top anti-virus (AV) performers, sorted by their strengths and who they’re useful for. (Although many of these programs are free, or have a free version, that’s not the reason they were chosen.)

Malwarebytes (Malwarebytes Corp.)

Who it’s for: PC users who’ve already been infected and need malware removal

Summary: Malwarebytes is great at what it says it does—the detection and removal of existing malware—a claim that cannot be made of all of its competitors. The free version of Malwarebytes installs easily, which is a boon for systems infected with malware that fights back against anti-malware installations. After installation it mercifully does not require a restart to activate, which sometimes exacerbates the problem. The interface is decidedly spartan, but it has the most comprehensive ability to remove malware around. If Malwarebytes doesn’t remove what ails your computer, free updates come often enough that it’s likely the menace will be caught in time. There is also a PRO version of Malwarebytes for $24.95 that ups protection to real time, and features scheduled scanning, just in case.

avast! (AVAST)

Who it’s for: PC users who need boot-time scans and a permanent, low processor-intensive background anti-virus

Summary: So you’ve got some malicious software so bad that it needs to be eliminated before Windows even boots? Here’s where avast! shines. It has support (even for the free version) on call to help you in this process if things get tricky. Plus, it works as a pretty good always-on AV for the background on computers that can’t afford to have a lot of processor time taken up (for example: computers still using Windows XP). Its detection and removal isn’t top-of-the-line, but it’s more than enough for home or business use if your operating system is getting on in years.

Ad-Aware (Lavasoft)

Who it’s for: PC users who have hard-to-detect malware and those who need ongoing malware blocking

Summary: Ad-Aware doesn’t do anything radically different from the previous two entries, but it’s a great all-around AV that will do in a pinch. It installs easily, it detects more viruses than the average AV, and it gets rid of those pesky files instead of simply quarantining them (a practice that other AVs will use to hang over your head should you choose to uninstall them). Plus, unlike a lot of the old-school, paid, always-on AVs, it won’t give you many false positives, interfering with or blocking programs that it deems suspicious but you know are on the level. Of course, if you’re the paying type, Lavasoft offers a Pro Security version of Ad-Aware that can throw up a firewall, protect you while banking, and scan your external storage.

Sophos (Sophos)

Who it’s for: Mac users who want to be absolutely sure of their protection from malware

Summary: Oh, to still be in the halcyon days of Mac malware, when the worst you could get was a misspelled endorsement for Michael Dukakis or a surprising German folk tune. Despite rumors to the contrary, malware has been known to pop up on the Mac from time to time. Some malware programs are written specifically for Macs, and some overachievers even work cross platform. So, if you’re in the market for Mac anti-malware, look for Sophos. It offers the standard features—scan at your leisure, on a schedule, or on access. Additionally, it’ll prevent your browser from accessing sites that host malware, and it’ll scan your downloads for potential surprises, removing or quarantining those it might find.

AVL (Antiy Labs)

Who it’s for: Android users who want anti-malware without any fancy features gumming up the works

Summary: AVL, available on the Google Play store for free, keeps malware away from your tablet or phone without any obvious drawbacks. It scored higher than average in detecting malicious apps, it doesn’t impact the battery life nor slow down the device, and it doesn’t pipe up when you try to install legitimate software. It won’t block calls or filter messages, but it’s one of the best pure manifestations of anti-malware removal for Android systems.

In closing, it’s important to note that no anti-malware program will protect against everything. Malware is a booming business, and anti-malware companies by necessity continually play a game of catch-up in updating their watch lists. Learning what not to download or click is a fundamental part of learning about the internet, and it’s not something mastered overnight. Although the first line of defense is the user, the powerful backup that these programs provide is certainly nothing to sneeze at.