THE DOWNSIDE of buying a cheap Windows computer these days is the amount of pre-installed junk it comes loaded with. There is no escaping the third-party “craplets” and “junkware” that litter the screen or taskbar—with free offers for this and that, trial versions of anti-virus software, utilities that promise to speed up the machine, others that offer to make internet searching more secure, even tools for removing unwanted junk (so they can add more of their own).

If their nagging pop-up presence were not bad enough, these unwanted applications—often running silently in the background—can harm the host they infect, by cluttering its memory, grabbing crucial processor cycles, clogging data channels and draining the battery. Some even sneakily track the user’s comings and goings on the internet. Their biggest crime, though, is to slow the infected computer to a crawl.

None of this junkware is there for the user’s benefit. It gets installed in the factory strictly to bolster the maker’s bottom line. Being so cut-throat these days, the commodity computer business has the slimmest of margins. The few pennies the maker receives from software firms for installing their dubious offerings on every machine can add up to a tidy sum. Most consumers accept having either to live with the junk, or to go to the trouble of cleaning up—“decrapifying”—the computer as part of the deal for getting such a relative bargain at so reasonable a price.

Some manufacturers sell “clean” versions of their computers for $20 to $30 more. Others offer to decrapify a purchased machine for an additional fee. Microsoft has adopted a different approach. To show its Windows operating system in the best possible light, it offers junk-free “Signature Edition” versions of many popular PCs through its online store. On average, Signature Edition PCs start up 104% faster and can be shut down 35% quicker than equivalent machines stuffed with the usual junk.

Your correspondent recently bought a Signature Edition of the Hewlett-Packard Stream 7 tablet from the Microsoft Store for an unbelievable $79. The sleek, black HP tablet, running Windows 8.1, came with all the usual complement of cameras, radios, sensors and other features, plus a free year’s subscription for Microsoft Office 365 (worth practically as much as the machine itself) and a $25 gift voucher. The bare tablet alone, without any of the extras, was listed at $99 on Hewlett-Packard’s own website. With its uncluttered start screen and clean memory, the little Windows tablet has proved a paragon of good behaviour.

At the other extreme are PC makers like Lenovo, the Chinese firm that acquired IBM’s personal-computer business back in 2005. As the world’s largest PC maker by volume and one of the industry’s most efficient producers, Lenovo does not need to stoop to such money-grubbing antics. Yet, it does—aggressively so. Or did, until a few weeks ago.

That was when researchers found that some of Lenovo’s laptops sold between last September and this January contained a serious security flaw. The source: a preloaded piece of adware called Superfish—a visual search engine that captures images users see online, and then shows them adverts of similar products. Unfortunately, Superfish replaced the security certificates used by websites with a universal and easily cracked one of its own, allowing attackers to steal users’ credit-card details and other personal information.

Superfish swears its software is safe, blaming an Israeli firm called Komodia that supplies the library of security certificates used by Superfish and other adware developers. Researchers have found at least a dozen other pieces of junkware capable of subverting the familiar HTTPS security protocol used by commercial websites to protect their customers. All, apparently, rely on Komodia’s library of security certificates to function. Some even leave a computer vulnerable after the source of the trouble has been removed.

Lenovo has apologised for causing its customers to become susceptible to attack, and has promised not to pre-install the Superfish visual-discovery software again—though it has not exactly sworn off junkware altogether. In future, the firm says it will publish a full list of the software pre-installed on each PC it sells, so users know what to remove or keep. It has also rushed out tools for removing Superfish and its related files, and arranged for the anti-virus makers Symantec, McAfee and Microsoft to do the same.

The whole sorry Superfish affair raises questions about whether stuffing computers (and, increasingly, mobile phones, too) with junkware can cause more trouble than it is worth for makers. Certainly, Microsoft is winning plaudits by offering customers junk-free products at a fair price, while Lenovo faces an uphill struggle to overcome its seriously tarnished reputation. The brand equity of the two firms could not be heading in more opposite directions.

For computer users, the issues are no less significant. Do they wait around for something like Superfish (or its even uglier cousin, PrivDog) to happen? Or do they take preemptive action immediately after acquiring a new machine? There are those who swear by reformatting the hard-drive and reinstalling the operating system from scratch. While this may be overkill, wiping the hard-drive clean will certainly purge a machine of any unwanted junk. But it will also remove all the useful software as well, all of which will then have to be reinstalled after a clean copy of the operating system has been re-loaded and brought uptodate.

There are easier ways of expunging unwanted junk from a new computer. Providing they do not stick their claws in as deep as Superfish, most of the craplets that get pre-installed by PC makers can be removed by simply using the Windows uninstall feature (found in Control Panel>Programs>Uninstall, or by right-clicking an active tile on the start screen). The task can be automated using a free tool called PC Decrapifier, which will recommend what garbage can be safely removed, and what should be left well alone.

Whether run manually or otherwise, simple uninstall programs (including the one built into Windows) can still leave a lot of detritus in the operating system’s registry. While your correspondent is a firm believer in not tinkering with the Windows registry, he has long relied on a free utility called Revo Uninstaller to dig out all the extraneous files, folders and registry items left behind after a program has been uninstalled. So far, Revo has never let him down—unlike some of the “registry cleaners” that promise to speed up a cluttered computer. These should be avoided at all cost.

A word of warning, though: check carefully all the registry items that Revo identifies as debris before giving it the go-ahead to blast them into oblivion. If a registry link contains the actual name of the uninstalled program, then it is a safe bet that it can be checked off for deletion. Those that have no such reference are best left alone. And should the removal process fail for some odd reason, fear not: Revo automatically makes a “restore point” before setting about its business. If necessary, the registry can then be rolled back to a prior condition.

Finally, a tip for those who think their computer may be harbouring the Superfish certificate that caused all the trouble. Open up the PC’s certificate manager (ie, run the Windows program certmgr.msc) and then click on “Trusted root certificate authorities” in the manager’s left-hand panel. Next, double-click “Certificates” in the main panel, and scan the trusted certificates listed. If the entry “Superfish Inc. Visual Discovery” is present, right-click it and delete it forthwith. If it is not there, rest easy until the next shoddily coded craplet causes mayhem. Alternatively, pay the premium for a Mac, or dump Windows and install a free copy of Linux. Either way, users will sleep easier, free from junkware—which, through no fault of Microsoft, continues to plague the world of Windows.